I am experiencing severe graphical corruption (see pictures below) when I try to switch from X to a console. This only happens with nvidia drivers version 9755 & 9746. I also tried 8776, 9629 and 9631, ... they all worked fine.
Steps to reproduce:
Start, boot into X (The boot-splash displays correctly)
-> only gibberish on screen
-> Back in X, everything displays ok.
Shutdown, X exits
-> gibberish instead of shutdown-splash
Start, tell grub to boot into console
-> Display is fine in console
Start X, quit X
-> Should be back in console, but only rubbish on screen
So you can see: Console works as long as X has not been started. If X was started once the console will no longer work.
The kernel option "vga=..." seems to have no influence on this behavior.
This is how it looks like right after Pressing Ctrl-Alt-F1:
A small part at the top is totally corrupted, below that is some kind of ghost picture of the last view of my X-Servers contents.
It gets worse with time: