nVidia driver update today: renders X11 unusable

[O. Hartmann]

Andriy Gapon wrote:
> Question to those having this problem - what kind of nVidia hardware do
> you have?
> Is that something that is based on G80 GPU or later (GeForce 8XXX or later)?
> I see that there is already version 2.1.12 of nv driver (in xorg
> repository) that is supposed to fix CPUToScreenColorExpandFill function
> for G80 cards.
> 

Well,
the problems I have are related to a nv8600GTS based board, this is, as 
far as I know, a G8X-based graphics board. Nearly 3 months ago some 
weird behaviour started to be static on the same hardware, Xorg wasn't 
capable of resetting the terminal is was bound to and presented me funny 
blinking block graphics on the screen. The Xorg server could oly be 
revived remotelly by killing the Xorg or within a running session by 
killing the Xorg for logging off. This problem has gone with today's 
update, but now my box (nv8600GTS) and the one of a collegue is rendered 
unusable.
My private box runs with a nv6800GT board and there Xorg freezes now 
very often and renders the box unusable, too.

I'm very unpleased about the situation, because it is impossible to do 
reasonable work.

How can I selectively 'downgrade' a port?

Regards,
Oliver

P.S. Sorry about some weird formatting, I'm typing blind, I see 'censor 
black bars' all over my screen, even in Thunderbird, Firefox ...).