Windows 7 - Club 3D AMD HD4350 randomly not detected by system

I hope somebody can help me find an answer

First my specs
Acer Aspire M3640 with Intel Dual CPU E2180@2.00Ghz
2Gb RAM
Windows 7 Ultimate 32bit fully updated
Club 3D AMD HD4350 AGP graphics card
My system has an onboard nVidia geForce 7100 Revision A2 / nForce 630i Revision A2

Most of the time my graphics card is working fine but sometimes (and to often to my liking) after a reboot, my system does not see my AMD and will send my video signal trough the nVidia onboard GPU and it might take several restarts before the AMD is seen again.

Anyone can tell me what i can do to prevent this or what to look for in my bios to disable the nVidia? I already checked but see no reference to a gpu in there.

thanks in advance

Whizzy

The latest bios is from 2008: R01-B4. I was hoping for a bios newer than this. And I don't see any support documentation online. One possibility is your 250W power supply is too small. You may need to upgrade it.