Re: AECS3 not refreshing video....HELP please!

Thanks for the tips Mr. LaRonde. I have a similar problem when I render out to dv Ntsc at 23.98 some downsized/downrezzed HVX 960x720 23.98 footage. I have a 8 Core MacPro 3.0, 6gb ram outfitted with both the ATI Radeon HD 2600 XT 256 VRAM and NVIDIA GeForce 8800 GT 512 VRAM cards. My DELL 2009W is attatched to the latter with a resolution of 1680x1050@60 Hz. It's a work comp so that's how they ordered it.
I just edited a music video 2 weeks ago with no problems, same type of footage from the HVX. I was even able to get the multiprocessing to speed up renders until towards the end that started getting hincky. I then cut it (mp) off and had no further problems. Then, this week as I was chuggin along, I started getting the weirdness of my undo/redo being greyed out, "AfterEffects needs at least 2 frames for playback" warnings during ram previews, my renders to dv-ntsc all freezing on the last frame of the render and audio being in sync when it feels like it when I bring it back to FCP 6. I had been using the workaround of just canceling the render and bringing the movs into FCP. I don't know what I did to get the out of sync files to render properly when I did fix the problem. I did it all, emptying every cache I could in AE, restarts, changing the ram cache and % ram dedicated to AE and FCP. But today the buggaboo doesn't wanna let me finish my video. Yesterday everything was fine.
I did not know about the lofty OpenGL claims of Adobe about AE, I was stoked and thought I was driving a nuclear sub after being stuck on a G4 PB the last 4 years. Do you happen to have a FAQ posted anywhere with your suggested Mac Pro configurations? Thank you and sorry for the long explanation.