I've been using Procaster for the Mac since about the day it came out. I can say that things were going well until you updated to .0.18, and now the problem I had then has gotten worse since I updated to .0.20.
The problem? Constantly disconnected. If it was my cable connection, I would understand, however the real problem comes after the disconnection. Procaster will continue to try to connect countless times, but then it will freeze at the last moment of connecting, pop back up like I'm live, then suddenly disconnect once again. When this happens, I can not stream for a good 4 or 5 hours before it'll stop doing this, and this is after restarting my computer 2 or 3 times.
Please look into this bug. I'm using a Macbook laptop, with 4 gig RAM, and using the OS 10.6.2.