Firewire/Geoforce2/KT133a installation problems

Hi all, interesting one thats been giving me a few problems recently.
W98SE, Lucent Dv-1000 IEEE 1394(basic pci firewire card), Geoforce2 MX200 AGP, Chaintech KT133a.
Everything works fine until I try and insert the Firewire card. I've had everything from no video at boot up, ie at post, to invalid display settings. Basically it is almost impossible to get to windows, the screen either blacks out after login screen, Invalid Display settings message then black out. Either way it seems the Firewire is upsetting the Graphics card. I have reinstalled latest drivers for the graphics cards, made sure there are no IRQ conflicts etc, re-installed windows. but all to no avail. However, 'once' it installed and worked great, till i rebooted then back to the drawing board.
I'm completely at a loss now on what to try next. If it hadn't been for the fact that it worked correctly once, i would have said that they were just totally imcompatiable.
HELP !!!

 

Do you have the latest BIOS-update? Also Windows-updates (like DirectX)?