As I mentioned in the 1.0rc2 notes, RC3 will have a fix for users using Speex at 8kHz and 16kHz getting temporarily banned when they try to transmit. This is the only change in this version.

We finally identified an unknown value that we’ve been searching for a couple months now. This behavior would not have affected anyone connecting to a personal server. It seems that the bug Luigi reported in the official Ventrilo client was fixed for the hosting companies’ version of the server.