Occasional black screen with mouse pointer when power adapter plugged in

Hi all,
I am running openSUSE 11.3 with KDE 4.4.4 on a Thinkpad T61p with an nvidia graphics card. (nvidia driver version: 256.53) I noticed some instances where I get a black screen when my power adapter is plugged in.
One of those instances is when I suspend to RAM on battery power, and then turn on, and afterwards plug in my power adapter. I get a black screen with only the mouse pointer. If I unplug the laptop I can see everything again. I plug back in, everything is gone. If I restart X, the problem is solved but it is not always acceptable to do that.
Can anyone suggest any permanent solutions?

I may not have a right answer here, but I vaguely remember these symptoms being discussed previously. (Search these forums and I’m sure you’ll find similar threads). Anyway, see if these are relevant

nVidia PowerMizer powersaving/cooling in Linux (updated) | Nobody was Born with Linux Knowledge

Ubuntu Forums - View Single Post - nvidia driver causes lock-ups, black flashes, hangs (continued)

Fedora 12 freezes - Page 6 - FedoraForum.org

http://tutanhamon.com.ua/technovodstvo/NVIDIA-UNIX-driver/

If you don’t have /etc/X11/xorg.conf present, then you could try adding the following line to /etc/X11/xorg.conf.d/50-deivce.conf instead.

Option  "RegistryDwords" "PowerMizerEnable=0x1; PerfLevelSrc=0x2222; PowerMizerLevel=0x3; PowerMizerDefault=0x3; PowerMizerDefaultAC=0x3"

IIRC, the general idea is to prevent the performance mode changing when switching between battery and AC, because that could cause problems for some users.

Maybe someone more familiar with nvidia hardware can offer a more definitive solution.