i have been running an a7n266-e w/1700+ xp stable (prime95 torture test 24/7 + q3a demo loop @ night) for the past few days. the pci bus is locked @ 33mhz regardless of the fsb. i also believe that the agp bus is locked @ 66mhz, but i haven't tried it yet. the board has a bios toggle where you can unlock the agp bus and let run overclocked. right now i'm running:
cpu: 1.6275ghz
agp: 4x 99mhz
fsb: 148mhz
pci: 33mhz
ram: 396mhz
according to the manual the agp overclocking only really works well if you're using the onboard video. one nice thing about the onboard video is that it's faster than a gf2mx200 since it's using the system ddr (which is even faster if you overclock) instead of sdram. it even overclocks better. i was able to get the core clock up to 220 mhz stable--mebbe even more but that's where the overclock slider stopped. my old gf2mx200 only made it up to like 200 before it'd start crashing.