Index: icefaces/ace/component/src/org/icefaces/ace/api/UIData.java
===================================================================
--- icefaces/ace/component/src/org/icefaces/ace/api/UIData.java	(revision 25241)
+++ icefaces/ace/component/src/org/icefaces/ace/api/UIData.java	(revision )
@@ -31,18 +31,18 @@
 import javax.faces.context.FacesContext;
 
 public class UIData extends javax.faces.component.UIData {
-    private String baseClientId = null;
+    //private String baseClientId = null;
     private StringBuilder builder;
 
-    @Override
-    public String getClientId(FacesContext context) {
-        if(baseClientId == null) {
-            baseClientId = super.getClientId(context);
-        }
+//    @Override
+//    public String getClientId(FacesContext context) {
+//        if(baseClientId == null) {
+//            baseClientId = super.getClientId(context);
+//        }
+//
+//        return baseClientId;
+//    }
 
-        return baseClientId;
-    }
-
     @Override
     public String getContainerClientId(FacesContext context) {
         String containerClientId = getStandardContainerClientId(context);
Index: icefaces/ace/component/src/org/icefaces/ace/component/datatable/DataTable.java
===================================================================
--- icefaces/ace/component/src/org/icefaces/ace/component/datatable/DataTable.java	(revision 25809)
+++ icefaces/ace/component/src/org/icefaces/ace/component/datatable/DataTable.java	(revision )
@@ -568,31 +568,132 @@
         if (tableWrapper == null) tableWrapper = (getDataModel() instanceof TreeDataModel);
         return tableWrapper;
     }
-    // Overridden from custom UIData impl because build process requires UIData, at
-    // a point where TreeDataModel will not have the dependencies required for compilation.
+
+    private String baseClientId = null;
+    private int baseClientIdLength;
+    private StringBuilder clientIdBuilder = null;
+    private Boolean isNested = null;
+    public String getBaseClientId(FacesContext context) {
+        if (baseClientId == null && clientIdBuilder == null) {
+            if (!isNestedWithinUIData()) {
+                clientIdBuilder = new StringBuilder(super.getClientId(context));
+                baseClientId = clientIdBuilder.toString();
+                baseClientIdLength = (baseClientId.length() + 1);
+                clientIdBuilder.append(UINamingContainer.getSeparatorChar(context));
+                clientIdBuilder.setLength(baseClientIdLength);
+            } else {
+                clientIdBuilder = new StringBuilder();
+            }
+        }
+        return baseClientId;
+    }
+
     @Override
     public String getContainerClientId(FacesContext context) {
-        String containerClientId = getStandardContainerClientId(context);
+        if (context == null) {
+            throw new NullPointerException();
+        }
+        return this.getClientId(context);
+    }
 
-        int rowIndex;
-        String rowId = "";
-        if (isTreeRootNode()) {
-            TreeDataModel rootModel = (TreeDataModel)getDataModel();
-            rowIndex = getRowIndex();
-            if (rootModel.isRootIndexSet()) rowId = rootModel.getRootIndex() + "." + rowIndex;
-            else rowId += rowIndex;
+    @Override
+   public String getClientId(FacesContext context) {
+
+        if (context == null) {
+            throw new NullPointerException();
+        }
+
+        // If baseClientId and clientIdBuilder are both null, this is the
+        // first time that getClientId() has been called.
+        // If we're not nested within another UIData, then:
+        //   - create a new StringBuilder assigned to clientIdBuilder containing
+        //   our client ID.
+        //   - toString() the builder - this result will be our baseClientId
+        //     for the duration of the component
+        //   - append UINamingContainer.getSeparatorChar() to the builder
+        //  If we are nested within another UIData, then:
+        //   - create an empty StringBuilder that will be used to build
+        //     this instance's ID
+        if (baseClientId == null && clientIdBuilder == null) {
+            if (!isNestedWithinUIData()) {
+                clientIdBuilder = new StringBuilder(super.getClientId(context));
+                baseClientId = clientIdBuilder.toString();
+                baseClientIdLength = (baseClientId.length() + 1);
+                clientIdBuilder.append(UINamingContainer.getSeparatorChar(context));
+                clientIdBuilder.setLength(baseClientIdLength);
             } else {
-            rowIndex = getRowIndex();
-            rowId += rowIndex;
+                clientIdBuilder = new StringBuilder();
             }
+        }
+        int rowIndex = getRowIndex();
+        if (rowIndex >= 0) {
+            String cid;
+            if (!isNestedWithinUIData()) {
+                // we're not nested, so the clientIdBuilder is already
+                // primed with clientID +
+                // UINamingContainer.getSeparatorChar().  Append the
+                // current rowIndex, and toString() the builder.  reset
+                // the builder to it's primed state.
+                if (isTreeRootNode()) {
+                    String rootIndex = ((TreeDataModel)getDataModel()).getRootIndex();
+                    if (rootIndex != null && !rootIndex.equals(""))
+                        rootIndex += "."+rowIndex;
+                    else rootIndex = ""+rowIndex;
+                    cid = clientIdBuilder.append(rootIndex).toString();
+                } else
+                    cid = clientIdBuilder.append(rowIndex).toString();
 
-        //TODO: raise reliability.
-        if (rowIndex == -1) return containerClientId;
+                clientIdBuilder.setLength(baseClientIdLength);
+            } else {
+                // we're nested, so we have to build the ID from scratch
+                // each time.  Reuse the same clientIdBuilder instance
+                // for each call by resetting the length to 0 after
+                // the ID has been computed.
+                if (isTreeRootNode()) {
+                    String rootIndex = ((TreeDataModel)getDataModel()).getRootIndex();
+                    if (rootIndex != null && !rootIndex.equals(""))
+                        rootIndex += "."+rowIndex;
+                    else rootIndex = ""+rowIndex;
+                    cid = clientIdBuilder.append(super.getClientId(context))
+                          .append(UINamingContainer.getSeparatorChar(context)).append(rootIndex)
+                          .toString();
+                } else
+                    cid = clientIdBuilder.append(super.getClientId(context))
+                          .append(UINamingContainer.getSeparatorChar(context)).append(rowIndex)
+                          .toString();
 
-        StringBuilder bld = getBuilder();
-        return bld.append(containerClientId).append(UINamingContainer.getSeparatorChar(context)).append(rowId).toString();
+                clientIdBuilder.setLength(0);
-    }
+            }
+            return (cid);
+        } else {
+            if (!isNestedWithinUIData()) {
+                // Not nested and no row available, so just return our baseClientId
+                return (baseClientId);
+            } else {
+                // nested and no row available, return the result of getClientId().
+                // this is necessary as the client ID will reflect the row that
+                // this table represents
+                return super.getClientId(context);
+            }
+        }
+    }
 
+    private Boolean isNestedWithinUIData() {
+        if (isNested == null) {
+            UIComponent parent = this;
+            while (null != (parent = parent.getParent())) {
+                if (parent instanceof UIData) {
+                    isNested = Boolean.TRUE;
+                    break;
+                }
+            }
+            if (isNested == null) {
+                isNested = Boolean.FALSE;
+            }
+            return isNested;
+        } else return isNested;
+    }
+
     public void setColumnOrdering(String[] indexes) {
         ArrayList<Integer> ints = new ArrayList<Integer>();
         int i;