I'm not really sure how to ask this, but here we go. I use After Effects CS6 version 220.127.116.11 in a 7 core Windows 7 computer with 8 gigs memory. It has always worked fine in the past. I also have Premiere CS6 on the same computer and have no problems with that at all. The problem is purely in AE. I shoot video primarily in 1280x720p. Recently whenever I do an effect in AE, be it a chroma key, a mask, anything involving 2 or more pieces of footage, the rendered footage has a tiny (but visible) shift continuously throughout the image. It's hard to explain what it looks like...it's like many parts of the image shift around very slightly (but again visibly) about 2~3 times a second.
If I import video into AE, then do nothing to it, then render it, it comes out fine. And if I do an effect with a single piece of video (like add a flare) it's good. But if I try any effect with 2 or more shots, I get this problem. I have not installed any other software on this computer. I have not has this happen in the past (same setup). The only thing changed is that I went to a different camera (my only present camera) in production. I suppose I should add more info, but I can't think of more to say. Any ideas?? Thanks!
After some checking around I discovered that, being the hottest months of the year, we have an older A/C unit running nearby. We'll test it of course, but could this be the cause??