I reinstalled WUU so I could have a log file.
Part of the problem does seem to be that my attempts to uninstall WUU when I was running Tiger were not successful. I tried to delete anything that mentioned WUU and completely redid my WoW Addons after WUU and Tiger caused WUU to freeze and my addons were in such disarray I just started over.
My log file can be found at http://l.g.connor.googlepages.com/WUU.log
I run Leopard and am trying to use WUU
Today I installed version 1.7.567 and ran it. My WoW install was detected and I chose 'Yes.' WUU closed without notice.
I deleted WUU, the folder out of Application Support and the folder out of Preferences, and then installed version 1.6.446.
I then ran WUU. I found my WoW folder when prompted and again WUU simply closed without without notice.