Just got a Vivotek PZ7132 Friday so I wrote a web enabled interface for PTZ control so I don't have to access the camera directly to do that nor use Windoze. Firefox 3.5.8 in Linux immediately dies when attempting to access it, got a feeling it's due to the QuickTime plugin. Opera can access it but no video, puts a message up from Vivotek saying Please use Firefox, well I would if I could... Camera works in ZM just fine.
With this interface the camera responds to commands much much faster then when I initially tried it in Vista. Vista and/or that interface must have a lot of overhead.
You can get it here: http://www.curtronics.com/ftp/vtek-ptz/vtek-ptz.html