A good rule of thumb to follow is separate hardware=separate bugs.
The X1200 (mobile/integrated chip) problem seems rather intractable, although some people have had success disabling/reducing the amount of sideport RAM - see comments. #138 and #149.
The X800 problem should be easier to fix, althought the fact that it only happens when the hardware is cold could mean a hardware bug - does that card work OK on Windows? Can you please attach the output of lspci -vvnn for the X800 card?
A good rule of thumb to follow is separate hardware=separate bugs.
The X1200 (mobile/integrated chip) problem seems rather intractable, although some people have had success disabling/reducing the amount of sideport RAM - see comments. #138 and #149.
The X800 problem should be easier to fix, althought the fact that it only happens when the hardware is cold could mean a hardware bug - does that card work OK on Windows? Can you please attach the output of lspci -vvnn for the X800 card?