I installed the frameworks and add-on's to Visual Studio 2005 v8.0.50.727.42 and found that all the items in my Toolbox disappeared and some items appeared more than once in other menus.

Apparently if you right click on one of the toolbox control headings, (common controls for example) and select reset toolbox

then right click again and select show all...

then they will be all displayed (with them grayed out)

then right click again and select Reset Toolbox...

should take about 30 seconds and they will all reappear

If this doesn't work you can also try clearing out the cache files for the Toolbox in C:\Documents and Settings\<username>\Local Settings\Application Data\Microsoft\VisualStudio\8.0