kUbuntu-9.10 64-bit, current updates
What I expect to happen: On bootup, seeing text and then greeting screen.
What is actually happening: During bootup, either from cold or restart, it appears that kdm is being started twice. It starts once before the video driver is loaded, producing an error screen saying the fonts aren't loaded, and the "low resolution" mode screen. Escaping out of these screens returns to the text, and then the regular greeter screen appears normally.
There is another related problem, in that the "rescue mode" is unusuable. Booting into rescue mode produces the menu. which is immediately overwritten with bootup text. Pressing Enter repeatedly produces an alternation between the "root@machine" prompt and the "Machine Login:" prompt, making it impossible to use the console.
I have disabled all kernel options such as vga= and splash, this does not help.
I have also discovered that after a "normal" boot, the usual bootup text and login prompt appears on CTRL-ALT-F1, F2 thru F6 are normal (login prompt only), on CTRL-ALT-F7 there is a second set of boot text, and the graphical screen is on CTRL-ALT-F8.
The problem does not appear to be with kdm, X or the NVIDIA drivers themselves, but with a script that is starting them twice.
This might also be a security problem, if two separate graphical logins are being started.
As an experiment I switched from kdm to gdm using dpkg-reconfigure gdm. The problem goes away when using gdm. Text behavior on tty1 and tty7 are normal; graphics comes up on tty7 as normal.