The streamWriting configuration parameter is no longer supported and has been removed from the documentation for some time. However, there are still several references to this parameter in the core and in various components. These references should be removed. I did a search of the trunk to find all the files that have at least one reference to streamWriting (or isStreamWriting). Some of the files reference it in more than one place. The trunk and branch appear to be the same in this regard:

/Users/deryk/Repo/svn/ossrepo/icefaces/branches/icefaces-1.7/icefaces > find . -name *.java | xargs grep -m 1 -i streamWriting
./component/src/com/icesoft/faces/component/outputprogress/OutputProgressRenderer.java: if (domContext.isStreamWriting()) {
./component/src/com/icesoft/faces/component/paneltabset/PanelTabSetRenderer.java: if (domContext.isStreamWriting()) {
./component/src/com/icesoft/faces/component/selectinputdate/SelectInputDate.java: if (DOMResponseWriter.isStreamWriting()) {
./component/src/com/icesoft/faces/component/selectinputdate/SelectInputDateRenderer.java: if (!domContext.isStreamWriting()) {
./core/src/com/icesoft/faces/context/DOMContext.java: if (!DOMResponseWriter.isStreamWriting()) {
./core/src/com/icesoft/faces/context/DOMResponseWriter.java: private static boolean isStreamWritingFlag = false;
./core/src/com/icesoft/faces/renderkit/dom_html_basic/MessageRenderer.java: if (domContext.isStreamWriting()) {
./core/src/com/icesoft/faces/renderkit/dom_html_basic/MessagesRenderer.java: if (domContext.isStreamWriting()) {