Bug#250354: 2.6.5 kernel: Dialogs not shown correctly during base-config

[Frans Pop <aragorn@tiscali.nl>]

Additional info.

I just tried Beta 4 (with 'linux26') on this laptop.

Immediately after booting d-i:
- Initially display on vt1 is OK (language menu shown correctly).
- I immediately switch to vt2 and activate it... no problem.
  vt3 and vt4 are also correct.
- Switch back to vt1... major problems!
  The text from vt2 (or vt3 or vt4) is still shown, but with an overlay of
  red and white vertical lines and some random black splotches.

So actually somewhere between Beta4 and 20040513 things improved dramatically 
for _1st stage_!

'cat /proc/modules' (lsmod does not work with 2.6 in Beta 4) shows:
cfbfillrect
cfbimgblt
cfbcopyarea
vgastate
vga16fb
font
fbcon

So the same modules are loaded... Where is the difference???