Today, I upgraded Kubuntu from Feisty->Gutsy->Hardy, and I now have a problem with Kaffeine in Hardy that I did not used to have under Feisty: In most videos, I get a strange frame "jitter" that makes them unwatchable.

This is not a "stuttering" where the video plays slowly, and it is not a "flicker" where the desktop appears briefly underneath. Rather, the video jumps randomly between adjacent frames in the video, very quickly(!). Please note also that the sound plays just fine.

Oddly, this happens in both Kaffeine and gxine, but not in ui-xine or totem -- which is strange because all four of these players use xine under-the-hood. (Of these players, I'd prefer to use Kaffeine, since I prefer its user interface and integration with KDE. Plus, the other players seem to have their own user-interface bugs.)

I know this is not some sort of disk or streaming error, since this happens for videos that I play directly from my hard drive.

I have an nVidia NV28 [GeForce4 Ti 4200 Go AGP 8x] running the "nvidia" driver. I think it is set up correctly, since I can run glxgears and Quake3 just fine.

Has anybody else run into this?
(Or does anyone have any suggestions?)

Thanks for your help.