Screen flashing in laptop under tty

[Till Varoquaux]

The screen flashes (my guess is that the back turn on and off) pretty
quickly on my laptop when I'm in tty mode.

I've seen this under hoary (install cd) and breezy and in usplash, the
ncurse installer and standard tty.

The screen doesn't flash under X (thanks god) and this laptop (asus
w1000n with radeon mobility 9600) didn't "flash" when it was under
gentoo.

Since it starts to flash quite soon (when usplash kicks in or when the
ncurse installer starts) it should norrow down pretty much the things
that might cause this problem.
Switching to and from Xorg doesn't solve the problem: once the screen
has started to flash it does so under every tty. reset (bash command)
doesn't fix it either.

Cheers,
Till