I love transmission and I have been using it over Vuze until today. Not anymore.
I don't know if it's related, but something happened to my leopard this afternoon and it made me very upset. I had to do an archive/install system recovery to get everything working again.
I was downloading something when transmission became irresponsive and wouldn't start anymore. Everytime I tried to run the application, it crashed. It happened out of nowhere, I wasn't even on keyboard when it happened the first time. No matter what I tried (resetting settings, downloading again, etc) it would still crash as soon as I clicked on the .app icon on dock.
I tried restarting and unfortunately found my system unable to complete the restart process. It would give me the blue screen just before the login screen and would flash there for a while then get to the login screen. When I tried to type something or even waited for a bit, blue screen would take over again. The system kept this loop for about 40 minutes when I decided to restart in single user mode and check the file system using "fsck -fy".
After that I tried booting the system and it failed again. I tried using the restore DVD disk to repair disk permissions and it failed during boot again, same problem.
Then, I looked for the blue screen error during boot on google and tried the archive and install method that some dude describes in this forum.
I finished the instalation and the system booted fine. Transmission is still not working. I finished all the updates, deleted transmission for good and I'm using uTorrent for mac now.
Though it's still beta and lack a lot of features, as far as I can see, it gets speeds that transmission never got on my connection. At least, for now, everything seems fine again.
When I looked on google for a transmission crash problem, I found this thread and I wanted to share this information with the community. I don't know if it was really a transmission related problem but it happened when I was using it, the application never worked anymore (everything else appears to be fine) and I switched to uTorrent.
For the sake of safety, I won't use transmission anymore. :S