If you didn’t do that already reinstalling the Oculus runtime may be worth a try. And vorpX again after a full uninstall and reboot (important!).
If you dare to try that, uninstalling your av program completely may something else to try. Some av programs aren’t really deactivated if they are deactivated (hope that makes sense).
Personally I would recommend Microsoft Security Essentials (Win7), respectively Windows Defender (Win8). Free, and not a single issue with those so far.
If you can’t solve the issue, please send a mail to support |at| vorpx com for individual trouble shooting. May take a day or two until you hear back.