Problem with iBook G3 after ffmpegx usage

[AndyPanda]

I have experienced a problem with my iBook G3 under MacOSX Tiger after ffmpegx usage.
I installed the soft, all the additional stuff (mplayer etc.) and ran the program. When I tried to convert my first videos (to be more precise, when I dragged and dropped one of the first video files to be converted to the application screen) I've noticed that the iBook screen behaves strangely:
1. The color depth decreased to something like 16 colors
2. The screen itself flickers as if it were running with low refresh rate
3. All the video subsystem seems to show very low performance
It seems to me that there's some problem with video card driver (I have switched to Mac recently, so that is the first thing i would concider using PC). I have checked all the switches in System Preferences that concerned refresh rate, color depth etc., all seems to be fine. I have downloaded and installed the newest drivers from ATI site.

Does anyone can tell me, what's going on?

[Case]

I have downloaded and installed the newest drivers from ATI site.

I don't know if you did that before or after experiencing the problem, but...
Necessary video driver (updates) for OEM cards come from Apple on your Mac OS DVD or via Software Update. In general, only separate retail cards need drivers from the manufacturer. Installing drivers for the 'wrong' card/firmware (read: tweaked by Apple) may be a source of problems by itself...

[AndyPanda]

Afterwards. In general, can I just reinstall video drivers or restore some missing files without reinstalling all the OS? Can any ffmpegx components corrupt some original files or change such global settings?

[Case]

Afterwards. In general, can I just reinstall video drivers or restore some missing files without reinstalling all the OS?

Dunno. Never had to try that before with OS X.

The iBook G3 may have a hardware issue, for which there is/was a repair program.

Can any ffmpegx components corrupt some original files or change such global settings?

I'm pretty sure it doesn't do any of that. ffmpegX uses it's own files, which are not used by any other part of the system. ffmpegX doesn't change settings of other software.