Dave, could you take a look at this? I'll give you a demo if you like.. maybe its something that's changed recently but it worked in 02/07's optimised, but has since started hanging. steps to reproduce: 1) open search sidebar panel 2) select the "advanced" tab 3) check more than one engine (choose a category with more than one engine from the results tab if the category you're in has only one engine) 4) go back to the results tab, type in some text and click search. the content area should switch to a tree view which will list the search results. The browser then hangs. Sometimes however extremely slow response can be had from UI widgets. Otherwise a force quit is required.
this was found to be a rogue style attribute on a tree widget. closing!