jerky playback

Thanks for the quick replies and suggestions, which I have done, but it didn't help – the video playback still is jerky, stopping and freezing then playing slowly. I never heard of the 2 utilities, MacJanitor and Yasu, but I downloaded them and ran them both. Then rebooted. But the problem remains, video playback is very jerky.

The jerky snapping of the Finder has been considerably reduced, but still present, with the columns wanting to move back and forth laterally. Also, when renaming a clip in the Browser it gets flacky and the text jerks a bit. Other programs are working, but a bit strangely – when I open Word, a blank doc opens but the menu does not show up along the top of the screen, and same for Photoshop – but they are functioning.

I’ve been using FCP for many years and am quite proficient at it, but never ran into this problem. It’s running on a new G5 that has not caused any problems previously. Still hoping for more help, thanks.

Oh, and yes I did download a program from video.google called a video uploader, which is used to send video to their site. So I have uninstalled that and removed all traces before running the variou sdisk utilities. That was a great suggestion that might have worked, but didn't.

Success! Studio X, my hat's off to you. I had forgotten those basic first principles in my eagerness to fix the problem: pull the plug and take a breather. I did as told, taking a tea break, and now playback is smooth. Perhaps that google video uploader played tricks in my system and maybe the cleanup utilities helped straighten things out, I don't know, but it was you who came up with the final fix, thanks a million. Now my dream system is humming along once again.