There are no Video plug-ins in the trimmer. With video effects in the timeline, I have no issues with playback. It's when playing a video in the trimmer, trying to figure out what to edit out is when the crashes occur. I've never had issues with rendering the final video.

Additionally, this does not fix the crashing. It appeared to at first, but after about 15 minutes of Vegas use, it crashed as usual.

When you say that Vegas crashes after a certain amount of time in the trimmer, do you mean even if you aren't playing the video in the trimmer (I mean it crashes even if you just open the trimmer tool with an AVCHD clip and let it sit idle)? It's interesting that with just one thread enabled in your quad core computer that it now crashes just about four times later than before. That suggests that it has something to do with some resource running out, and now it takes four times longer with only one of four processors running and using resources. It would be interesting to watch your system resource utilization while you are running Vegas... press & hold CTRL+ALT+DEL and click on the Performance tab and watch what happens as time progresses until the crash.

Speaking of the 3-finger salute to bring up the Task Manager, I would suggest downloading and using Process Explorer instead. It gives you more information than Task Manager does.

About the Trimmer, you can do a Search to find the Pros & Cons of its use. I've never used it and do all my cutting on the timeline. Position cursor and type S to split the event and delete the unwanted parts. So unless you have a specific reason for using the Trimmer, I suggest you try your editing without it opting to do it in the timeline. Just a thought.

I'm not running out of anything. My RAM utilization is at most 35%. Vegas does not use over a gig of memory. And the memory usage is pretty constant.

It does not require that I play a video in the trimmer constantly. I'll start, stop, edit... get another clip, play it some, mark, add to timeline, play some more.... then boom. Vegas goes down.

A video must be actively playing in the trimmer to crash it.

Then don't use the trimmer.

If they put it in to use, it should work. How about I sell you a car but tell you to not use it because it doesn't work.

True enough. It's not that the whole car doesn't work, just some features, but it's still drivable. I don't use all the features my car has but I still drive it.

Is there a reason you "must" use the trimmer? I think you could get along nicely without it.

Don't get me wrong, you have a valid point in raising your concern. Unfortunately, other than the workaround I've suggested I think that's all you're going to get on this forum. It's not visited by the developers very often (if ever) so I suggest you contact Tech Support via the Support link above.

With v10 way overdue, I doubt you'll see a 9.0c release that would fix your issue, but I could be wrong.

Good Luck.