GA-71XE and AGP 2x

I have a Geforce2 GTS running on the GA71XE board. The board supports AGP 2x yet only 1x is enabled. How do I go about enabling AGP 2x ?? I have seen no obvious setting in the bios.

P.S I know that Powerstrip can force 2x but I'm looking for a more fixed change.

Thanks in advance

Andy