Adobe Premiere Pro CS3 Video effects & transitions not appearing in program monitor

[jezza7777777]

Hi, I am editing a feature film on my home PC, and before now have had great experience with Premiere Pro CS3. The film was done on HD and there is about 28 hours of footage, with about 20 gigs or so of space still left on my main hard drive.

But about a week ago I started to run into 2 problems:

1) If my timeline was more than 20 minutes long (just an approximation) the video effects and transitions stopped showing up on my Program Monitor. The effects are still there in my timeline but they are not showing up when I'm going through the movie in the program monitor.

2) CS3 keeps randomly shutting down/crashing, especially when I am adjusting/adding complex audio or video effects in the timeline.

Does anyone have any suggestions or help as to how I can fix these problems??? Your help would be much appreciated.

Thanks,
Jeremy.

[Agent]

Firstly, is it fully patched up?

Secondly, are you overclocking? If so, back off a bit and see if that helps with the crashing