In Windows 7, applications that need to modify their own installation files, such as Voobly or XvT or XWA, need to be run as administrator. Now that is perfectly fine, but there seems to be just one problem with that.
That is, Ventrilo, when run as normal user, doesn't see the key presses, pressed in an application run by the administrator, or more precicely if they're pressed when that application has focus.
If you want to be able to use push-to-talk in Ventrilo with XvT/XWA, run Ventrilo as an Administrator!
System: All There are common issues of graphical nature with X-Wing Alliance. The tranparency of the HUD might not work, the fonts may look awkward or the game may run with a poor framerate.
These problems have been Various Fixes addressed. Get the nvidia fix there and the font fix (cosmetic only).