There is a possible fix to the laggy audio that most people have been dealing with when using ventrilo:
1st: Have ventrilo run as administrator
2nd: Run the "troubleshoot compatability" tool by right clicking on the ventrilo icon. Go through the wizard and run as vista. Start the program from within the wizard and test to see if it works. Once you are happy save the settings.
I did this and haven't had a single lag issue. I ran it all weekend. There is a sticky on the ventrilo forums with additional steps if this doesn't work for you. Hope this helps.