When using a JSF 2.0 composite component that has an "id" attribute, the id will be rendered into the page instead of just passed through to the component. For example:

<div id="parentCon">
 <ice-cc:filterTable id="ourTable" bean="..."/>
</div>

Then the component code itself:

...
<ice:dataTable id="#{cc.attrs.id}"...
...

We would expect the id of the composite component dataTable to be "parentCon:ourTable". Instead it appears to render as "parentCon:ourTable:ourTable", because the id of the filterTable composite component is being rendered into the page as well. Basically "id" looks like a reserved name that can't be freely used as a composite component attribute.

To workaround you could use a different attribute name, for example 'fakeId="ourTable"' would properly render in the above example as "parentCon:ourTable". This breaks backwards compatibility and is more confusing for a user to work with.

Also note this issue causes problems for components that rely on id, such as the "for" of a dataPaginator.