i need help asap

[jakesully]

my powerdvd ultra could only play the menus and previews clearly, but when it gets into the actual movie, it flickers like crazy with green screen/ yellow zig zags, etc etc.(you could see some of the film, but in splitt second shots)

I could play planet earth(25 gig discs) normallly.
But I think it's because of the mpeg 4 codec in the newer discs?

Is there a special codec I could dl? I already got the latest patch from pdvd.

thanks.