It is worth a try; if that doesn't work then you can also try to run the
nvidia installer script again. When I was still using the nvidia
installer I had to run it again whenever xserver-xorg-core was upgraded.
I finally got around to trying this again ;).
No go on the reinstall, in fact, it failed with a couple of error messages, seems to
have clobbered libgl.so.1 in the process, causing me to have to reinstall it and X along in the process. Additionally, the nvidia driver is not installed, and I have to limp along with the 'nv' driver (sniff).
Along the way, it complains about libglx.so not being a symlink. Maybe I should try the
"debian way" - and I forget exactly how that is done :(.
The installer (on the nvidia run file) says also that it was writing to an installer log and I don't see where that log is, which of course would probably help me getting the system back to a state where I can use the accelerated features of my card.