Well I've always had this problem, just never thought there would be a way to fix it. But its worth a try.

I cannot preview my clips in the preview box in Sony Vegas 9.0 without any lag problems, no matter what quality I select (Best - About 0.5 fps, Draft - About 10 fps).

This is weird simply because my specs for my laptop aren't bad at all.

Windows Vista Home Premium
Intel Core 2 Duo Processor T5800
250 GB Harddrive
nVidia GeForce 9300M GS (256MB)
2GB L2 Cache

The other problem is that I cannot render one specific file, everything else works fine. This has no added effects, but only volume envelopes added to the clips (quite intense changes, but no video fx). This video is less than one minute long.

I get the error that Sony Vegas has low memory, and closing other applications may help. Yet this doesn't change anything. This happens before reaching a single percent. Either this, or it will render to say 4% before freezing (timer still goes up even though nothing happens)

I have changed number of rendering threads from 4 to 1, and changed the dynamic ram preview from 16 to 4 (Max available is 1024 ). No change.

Any help on these problems? I wouldn't be suprised if my specifications were bad, but they're not.