My Comp and 1080/720

Im trying to play some movies in 1080 like the new final fantasy trailers and some films but it just ends up and lags with the audio going ahead so its all out of sink and i don't know why. This also happens slightly when ive been playing a movie for like an hour with 720.
Read my comp stats from the side under my name
I have the latest ATI Drivers
When im Playing the movies im at 100% cpu, i would have throught my x1950 pro would be able to cope its good enough for most gaming (except the new stuff)

Which specific videos are you trying to play, and what app are you using to play them?

VLC has hardware acceleration options in the preferences which are needed for some PCs.

I had a P4-D 2.6GHz HT with an ATI HD3450 which had big problems playing 1080p - it played initially, but after a few seconds it would stutter or stop displaying things. Upgrading to an E8400 works great, and my HTPC's dual-pentium E5200 plays HD fine.

I think it will be a case of a non-HD-accelerated video card together with a non-dual-core CPU.

edit: I suppose it would also be worth checking temperatures and for fan (dust) obscructions. The Scaleo P case doesn't look that good in terms of airflow. And also check voltages and the condition of the capacitors on the motherboard.

Tryed VLC player, wmp, QT, bs player. I have them in to formats either MKV or MP4. The MP4 works best in QT and the MKV's in bs player. Maybe my comp just isn't gd enough :(
Il have to wait till i build my new comp yo watch them

Before i upgraded my htpc to a 9500gt, from a 1950pro, my cpu (x2 7750) ran at 40+% iirc playing blurays and now it rarely hits 20%, most of the time less than 10% so i would agree its more than likely your gfx cards lack of hd decoding thats the issue. Though a dual core cpu would also certainly help. Cheapest upgrade would probably be a new gfx card.