Sorry, I don't know anything about overclocking. http://www.anandtech.com usually has good info on that sorta stuff.

Make sure that the heatsink is right and on correctly. Use CPUCool to check the temperature at normal speeds. With that board, you should be able to bump the front-side bus speed up to about 180 MHz or more without problems. That puts the PCI bus at about 37-38 MHz; occasionally (but rarely), a PCI card will choke when overclocked that high. What brand of RAM? What PCI cards, if any?

I think the ram is crucialram, as for pci cards a network card and um a tv card. Sound card is inbuilt and the graphics card is a gfx 5200 in the agp slot

You may not be able to get that much from a 2600+.

They only released it in the Thoroughbred core. From what I've read, that particular core isn't very good for overclocking.

I suggest checking out www.tomshardware.com . They seemed to have some info somewhere on their site about it.

you may want to check jumpers on the board. The BIOS must work with the jumpers on the board. Be careful this is a great way to fry a mother board and chipset. consider good ventilation and cooling.

'The problem you are having is not your configuration, it's the A7N8X Deluxe. For some reason, the mobo has difficulties saving info in the BIOS. Just hope that Asus comes out with a bios revision to fix this problem."
Also, if you are having problems booting, Try this. Before you turn on your computer, Press and Hold the TAB button, and turn your computer on. When the memory screen comes up, let go.
For some reason, this forces the mobo to boot up no mater what. Well, is works for me. This is also from asus tech. wupport.

"a 2600+/333MHz FSB runs at either 1910MHz (Barton core). Or at 2150MHz. No AMD processor runs above 2200MHz. At 200MHz X 13 = 2600MHz, you are frying that procesor. You want to back it down to 166MHz X 13 = ~2160MHz if you have a thoroughbred core. 166MHz X 11.5 = ~1910MHz if it's a Barton core. Then slowly increase the frequency via the FSB and/or multiplier until unstable. Then back down until it's stable and not running too hot. A good starting point would be 10 X 200MHz = 2000MHz. And don't try for a 200MHz FSB unless you have PC3200 (DDR400). Overclocking RAM can cause all kinds of problems.
I hope you didn't fry that thing trying to run it at 2600MHz."

I've got a 1700+ Thoroughbred-B that says exactly the opposite.

And the Asus board listed is an nForce2 chipset based board. One of the good features about that is the PCI bus is locked at 33MHz, totally independant of FSB.

I'm not sure about the multiplier on the 2600+ being locked or not, but dropped to 11 and running the FSB at 200MHz shouldn't post too much of an issue.

And I don't own a the A7N8X Deluxe, but I remember it either having no jumpers concerning the CPU settings, or just a solitary one. Manual will bring truth to that.

the only amd processors that i heard that are good overclockers are the amd athlon xp 1700+ with the Thoroughbred b core and the amd athlon xp 2500+ with a barton core

they also came out with a barton core