I've never seen this one Marc. No issues with searching the help in V8c or V9 or V9a...By this I think you mean using the incremental search box inside the help? --
Yes, I have this problem with V8abc. I had to put a shortcut directly to the help file on my desktop. If I open help outside of vegas it does not crash. I contacted tech support on this and they had no help for me other than to comment that it may be related to my boot/system drive not being the "C" drive. I triple boot my machine and vegas normally runs from "F". Vegas 9 seems to be working ok in this respect.