I did a little research on the laptop...I found some info on a slightly different model, that apparently uses shared memory. Assuming that's the case here, your problem is probably that you're running out of RAM so it has to page in stuff from the hard drive.
So, stuff you could do; remove one or more mediaVPs. I think I'd go with effects; music doesn't use that memory, but you could try removing that. You certainly shouldn't be using mv_adveffects. removing mv_textures will get rid of shine and glow maps, so I wouldn't recommend getting rid of that except as a last resort, so models would be the next-to-last option.
If you get ahold of a recent build...anything 12/29 and later is incompatible with the third mediaVP 3.6.7 patch and later. However, one of the recent CVS builds will let you use the -img2dds option, which will compress all textures. In 3.6.7, I think there's an option "-pcx2dds" that you could use.
I don't know if I'd suggest going to 3.6.8-delta. It has more high-poly models, but has more media, so it might lag more.