B-bred 1700+ / AK35GT2 no go

Have the 'G' flash to Bios, but the 1700+ will not boot. Blank screen, no 'beep' , CDs lite up, hard drive indicator keeps running, but no boot.

Have heard the L5s on B-breds might be a problem with this mobo. This chip ran like a bandit on an 8K5A2+ (2300 Mhz 209x11) with no problem.

Pulled the chip, reinstalled my 1600+ Pal, all things work fine.

Any ideas?