Just in case someone gets bitten by something similar, I have noticed slightly different behaviour with the Vegas audio plugin scanner (on startup). I think it existed since b300, and is definitely in b314.

I also have CueBase installed, so given the path of (for example) C:\Program Files\Common Files\VST3, of course it was barfing on the Steinberg instruments and recording several event log errors. Upon exiting Vegas it would hang my entire system for 30 seconds or so, and eventually throw an error with ntdll.dll  

After pointing my VST Effect paths to each VST3 subdirectory appropriate for Vegas, all seems well.

Note that I do not have this issue with Sound Forge, or previously with Vegas b208.

Maybe it's specific to my system, but perhaps it might save some frustration for anyone with a similar setup.