Heyho, I'm having some problems with Vegas and hope somebody can help me out.
Whenever I set the "Video rendering quality" option above "Good (half)", the preview window turns red on some clips and freezes the program when I try to preview any frame of those. That ain't a problem while editing since I'm not previewing everything on maximum settings, but when I want to render any file, ofc I'm setting the "Video rendering quality" to "Best" in the Project tab. No matter what format I'm using, it crashes whenever it reaches one of those "corrupted" clips.
Works fine:

FUUUUUUUUUUUU-

I thought it might be the effects amount I got upon some clips since my hardware is pretty weak, but even when I disabled all of them, it kept crashing. I also tried changing the format of the source clips, but that didn't help either (well Fraps' codec doesn't seem to be the problem anyway since the clips use to work, just not on maximum settings). I've also tried disabling the preview on renderings without success.
Afterwards I tried some suggestions I found around Google & YouTube, but nothing actually helped of what I tried. Hope you guys got some ideas or sth else.
And my system specs:
WinXP 32bit SP3
MSI MS-7204
Intel Pentium D830 (2 x 3,0 Ghz)
Nvidia GeForce 7950 GT (512 MB)
Infineon <idk-the-product's-name> (3 GB)