Ati card problem

[Krzysztof]

Hello,

I had had ati drivers (Asus Radeon HD4850 512MB card, 64bit Ubuntu
Karmic) installed on my computer and everything was ok until
yesterday. I was working on open office Calc and used "paste special"
with transpose option and then my computer hung. I had to reboot it
with hard restart and when logged into Ubuntu the performance of the
card was very bad (still good in Windows, though). I uninstalled
drivers and it was better (default driver), but no graphic effects
could be installed. After new drivers installation again it works very
bad, so had to uninstall it again. Please help me to get back to
original state, when all was fine. Hope I don't have to reinstall
Ubuntu to get there.

Regards,
Krzysztow