Solutions from Ventrilo Users
(these are listed here due to unique configurations)
1. If you are running a motherboard with nVidia chipset and have "NVIDIA Forceware Network Access Manager" installed from the Forceware package try uninstalling it as it is an add-on you don't need that only conflicts with Vista.
2. Router w/Speedboost - http://forum.ventrilo.com/showthread.php?t=29288
3. Thinking Outside the Box - http://forum.ventrilo.com/showthread.php?t=35315
4. The Ventrilo2.INI file becomes corrupt. (this is rare but has been seen to cause connection problems)
Exit Ventrilo
Goto START > RUN and enter: %appdata%\ventrilo
Right-click on Ventrilo2.ini and select “Rename”
Give the file a different name
or
Delete the Ventrilo folder
Restart vent
Re-enter your username and server information
Mobile Wi-Fi/Broadband Adapters
Check the device configuration for "Proxy" settings and try disabling it.
http://forum.ventrilo.com/showthread.php?t=39591
(consult the device documentation for location of settings)
Verizon FIOS Firewall
http://forum.ventrilo.com/showthread.php?t=39948