It's been probably a year since I last used Pinnacle Studio 9+ for color correction with analog video, but I didn't have the problem you're referring to. It did, however, increase render times quite a bit.
You have a couple of possible causes:
* your machine may be too slow, or not enough memory to handle the task.
* you may be trying to apply multiple effects that do not "play well" together.
* you may need an update patch.
The Pinnacle user forums are probably your best bet for a knowledgeable solution.