jpetersen
Sounds similar to the problem I just had.
What happens if you play a sound file using the standard Windows Media Player?

I was just about to say that. you had a very similar issue you solved by disabling your onboard audio, HD, Exc in devise manager correct ?
smells the same here.

Unplug your audio interface and try to use your built in audio if you have any, see if the problem persists. Check your device manager and see if there are other audio devices like cameras and graphics card audio, disable them.
 
Run the plug in manager and try to disable any plugins that may not belong that were installed by other apps. It is probably a plugin that Platinum does not like running. 
 
Unplug printers and any other devices too. If you have Sonar pro also installed the two may be conflicting with shared files and plugins.