Happy Otter Scripts, wonderful tool. I especially use RenderPlus quite a bit an noticed that sometimes I would get "locked" out of an application during render. By locked out I mean I would just get a ding when trying to do anything in that application. It was generally Chrome this happened with but now I figured out what is going on.
When you set off RenderPlus the first thing that happens is the audio file is processed. If at the end of that audio processing when the frameserving starts you have a different application in the foreground, that process will in effect be "sandwiched" between Debugmode frameserver and Vegas, thus "locking" it out, or making it unable to be accessed or controlled. For me this was generally Chrome because I would have a quick look at the internet while waiting for a render to get going.
The workaround is easy. Just wait until RenderPlus start to actually serve video frames before moving to another application.
It was kind of confounding until I figured it out and thought I might be able to save someone else the trouble.
Mark