nforce2 realtek alc650 built-in chip not working

I have a Asus A7N8X-X mobo with a nForce2 chipset which brings a
Realtek ALC650 chip for the sound card. The XP drivers work fine until
I restart the system. Then, when I come to the logon screen, the 'logon'
sound plays about half-way through and the system hangs. If I restart
in safe mode and disable the sound card, when I reboot in 'normal' mode
I can login fine and re-enable the sound card to get sound again, but it is
a big PAIN. what am I doing wrong? what drivers are best suited for this
chipset??

thank you all for your time.

Start here,

Realtek

and work your way to the download page. You need the Realtek AC'97 driver for Windows 7 for that audio chip.

ok, I've installed the vista version of the driver from Realtek and audio works great until
all of a sudden, without a single warning or sign the sound halts and the computer freezes.
After that, everytime the system starts, when I get to the logon screen, as the logon tune
is playing back the sound 'tilts' and the machine locks again.
I have to re-start in safe mode and disable the sound, then RE-start (!) and re-enable the
sound.
What's up with the nForce2 built-in sound chip?!?!? is it incompatible with win7?
Should I get a separate sound card just to be able to have sound in win7?

thanks for your time.