I am trying to render 90 minutes project to BluRay template 15mbs mp4 on Vegas 9 and after 30 seconds strange error appears saying that system is low in memory. I restart the windows and it is still happening. what is going on?

How much RAM is installed in your machine?

4G
but I am rendering now to mpeg2 and it works very well; error only happens when I try to render to mp4!!!!

4G
but I am rendering now to mpeg2 and it works very well; error only happens when I try to render to mp4!!!!

Mpeg4 requires more work to encode as well as decode. no surprise there.

btw - which format to use mpeg ormp4 when rendering for bluray; is 25mbs mpeg better quality than 15mbs mp4? and what about BluRay players compatibility playing back mpeg and mp4?