Each time I try to download an mp4 instead of MP_ROOT/101MNV01 I see MP_ROOT/102MNV02 and when I choose it has two files with weird symbols on it.and when I download an mp4 it always fails.is it a virus or something?

Are you downloading from this site? Or do you say downloading as in sending the files to your PSP? Ive downloaded many movies both ways and have never had that problem. If sending the files to your psp make a folder in the root of your memory stick named MP_ROOT. Inside that folder make another folder named 101MNV01. You add your MP4 files to that folder.

since you have 2.7, you could upgrade to 2.8 and make a movie folder and save them there.
You can probably find a way around this without upgrading, but it's just a suggestion

Oh yeah, you could try formatting your memory stick

never heard of that...just format

where are you download it from
?ive never have ne probs with this site(link from this site)..dunno about other site though