Er....the CUSL2 family of boards drops from AGP4X to AGP2X at speeds above 140Mhz FSB.
To fix this problem, you need WPCREDIT or STUFFPCR and set the AGP registers...
Personally, I don't see much point in bothering about this, or why there is so much fuss over it since the real world performance gains between AGP2X and AGP4X are almost non-existent.