Im in the same boat as you basically.... i have an a8n-sli deluxe and an athlon 3500+ (Newcastle though) and i cant get over 2.3 without problems. I know my power supply is good enough, so its not that. I tried ocing again tonight and my date/clock reset to january 1st 2003....on my mb and windows. Not cool. What are the exact cinfigs power and speed wise that your trying to use? I try between 1.55 and 1.6 for cpu voltage, scared to go higher cause the max is 1.65 for that board and max usually is never good. Im not sure when something is set to auto if thats good or not....have you od'c your pci speed? I dont know if i should or not. I usually try and put the fsb to 220, the vcore to 1.55, multiplier to 11x, HTF to 5x, and dunno what to put the ram voltage to. I wish i knew what to manually adjust and what to keep on auto. Ive had no help at all from the different Asus utilities eg Cool n Quiet, AI Nos, they all sucked for me. All i know is if all i can oc to is 2.3 then that sucks. Also have you oc'd your ram at the same time as when your doing your cpu? Im not sure if ocing your cpu make your ram faster or not, i would assume so tho.
Athlon 64 3500+ / Asus A8N-SLI Deluxe
1gb Corsair DC Twin-X (512x2) Pc3200 LL
2x Asus EN6600GT w/76.10 Forceware (It Helps)
Sony DVD RW DRU-710A / Toshiba 16x DVD-ROM
Thermaltake Shark Aluminum Case w/Asus 4 in 1 Cool Ice CPU Fan
Sound Blaster Audigy2 ZS
3DMark 2003 ~ 14682