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.
try going back further... i had the same problem (half the time it wouldnt even run) and if i remember correctly, it was a 1.5.x some vers that worked, and after that i upgraded it and they all work now. :S hope that helps...