No it's not the only place it locks up.  There is one time or thing that seems to make my game lock up most often and that is right after getting killed.  The game locks up with the death message or whatever you call it on the screen.  For some (maybe all) deaths where this happens the screen has the red edges and distortion if you know what I mean - frozen in that moment between when you die and when you respawn.  When I saw it lock up in the weapon priority I got to thinking that it could be related because when you die you lose your weapons, the weapon display bar goes away and comes back when you respawn.

I also don't want to call it a crash because in these cases of locking up after death I can still get to the task manager (and end the ut3.exe process) when this happens, I don't get any error report from windows and UT3 doesn't create a dump file.

It could still be just related to the mysterious problem that seems to be on my motherboard.  I might still mess around with the ini files to see if I can figure out how to correct the issues in the weapon priority screen but so far I don't have it 100% predictable depending on which exact ini files I have in my folders.  Skyscraper is the map I notice lately where I think it's most likely to happen but I know it's happened on Shoebox, AnarchyHalls and OffTheRails.  Do I need to have any ini files for the maps to play the game?  I think you only need them if you want to run a server and have thought about getting rid of all the map ini files and see if I notice a difference that way.