Dimension XPS 600 CrossfireX BIOS update

Is there a BIOS update that will allow an XPS 600 system to detect and enable Crossfire support for the new ATI cards with internal Crossfire support (i.e. they don't need a dongle or bridge adapter linking each card to enable Crossfire).

I got a good deal on two Sapphres HD 4670 512 DDR3 cards to replace the X1900's in my box (one of them had just died).

The X1900 Crossfire were working nicely. So figured the 4670's should be plug compatible since the MoBo must support Crossfire. Well to my surprise, the ATI CCC and ATI Tray Tools both report that Crossfire is not enabled. Both cards are seen and working (Windows Device Manager (running XP Pro SP3) and GPU-Z both confirm this).

I swapped out each card and installed into slot 0 individually and both work fine on their own (just in case one card was suspect). When installed together, both cards do work and I can hang separate monitors off each card. But no Crossfire.

Sapphire Tech tells me that that my BIOS must therefore not support the newer CrossfireX with the internally enabled Crossfire.

I really don't want to go finding replacement X1900's nor do I want to just use a single 4670 without Crossfire, so I am hoping there is some sort of BIOS update/patch that I can flash to enable CrossfireX support for my box.

I suppose I can break down and buy a brand new PC but I am waiting until Windows 7 SP1 is released before I jump on it and get a new PC at the same time.

Are there other XPS 600 users out there with similar problems?

Regards,

John