OS X Help Viewer Freezes
To clear up the issue remove old aliases and .plist files
http://discussions.apple.com/thread.jspa?threadID=137902
:
... - before doing the above, check out ~/Library/Documentation/Help and /Library/Documentation/Help and scan the list clicking on each item to see if you have any orphaned aliases there (from apps you've trashed).
I went through the above steps with a malfunctioning Help Viewer and found they fixed the problem exactly once - until the Help Viewer was reinvoked.
Trashing aliases before doing the above made the Help Viewer stable again on my system.
:
Go to Users/Your_Name/Library/Preferences and delete the following files:
com.apple.help.plist
com.apple.helpui.plist (not in 10.5)
com.apple.helpviewer.plist
