i'm seeing that even when i collapse the left-hand nav section, it will render the entire tree at the beginning of the page render...and only after the entire tree is rendered will it collapse to the left and then render the rest of the page. i'm hoping that there is a way to tell the component not to bother rendered any of the tree if it's collapsed.
expand/collapse solution no longer exists. things were reworked to use a splitter pane between the navigation and content areas.
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-1278