No console text with GeForce 6150 and vga=0x307 after X start

[MadDogII]

After upgrading from Feisty to Hardy the text console (Ctrl+Alt+F1) stays black after X start.
This only happens when I set "vga=0x307" or "vga=0x31b" (others not tried) as kernel boot option.
Booting without vga parameter works fine for nvidia-glx-new. Using nvidia-glx package the display was distorted (but still readable).

Some information I would like to provide:

 lspci |grep VGA
00:05.0 VGA compatible controller: nVidia Corporation C51PV [GeForce 6150] (rev a2)
root@keroro:/boot/grub#

dpkg -l |grep nvidia
ii nvidia-glx-new 169.12+2.6.24.11-12.31 NVIDIA binary XFree86 4.x/X.Org 'new' driver
ii nvidia-kernel-common 20051028+1ubuntu8 NVIDIA binary kernel module common files

 uname -a
Linux keroro 2.6.24-12-generic #1 SMP Wed Mar 12 22:31:43 UTC 2008 x86_64 GNU/Linux