Originally posted by Andre
Well, in my case I think nothing is wrong in the BIOS as the graphic card works with WindowsXP.
No, XP might work even with PnP OS set to yes and/or Assign IRQ set to no. The philosophy of Linux is, don't duplicate work that is better done somewhere else (in the BIOS), which is what those two settings control. PnP OS set to no means that the BIOS will initialize all devices (which works much better). If it's set to yes, the OS will initialize some devices -- however, Linux won't. The kernel people have seen the lack of good documentation for the PnP spec, and the fact that the vast majority of BIOSes can initialize devices just fine with no help, and said "it's pointless to duplicate that functionality". Windows, on the other hand, duplicates it anyway.
Assign IRQ works much the same way. With it set to yes, the BIOS will give your graphics card an IRQ, which the OS will use. With it set to no, the OS should assign an IRQ if it's needed (and it almost always is...), but again, Linux developers thought "why? when the BIOS does a better job anyway?" and didn't code that functionality duplication in. Microsoft did.
In short, yes, these settings could be "wrong" in your BIOS, but XP would still work.