At some point the IDE would lock up whenver I pinned the toolbox open.
I “fixed” it by deleting the file toolbox.tbd found in %USERPROFILE%\Local Settings\Application Data\Microsoft\VisualStudio\7.1\
But a cow-orker of mine had the same problem, and deleting that file didn't work. So--best of luck if you are having this problem. If you know of an official fix for this, please let me know.