Cant set FSB to 133, A7V266MX/2400XP

[meganox]

Just got an Asus A7V266-MX and Athlon 2400+ XP. Runs just fine at 100MHz (all DIP switches OFF) but when I set it to 133MHz (DIPs 2 and 4 ON, according to the manual) the system won't boot. The board powers up OK and all the fans go, but it doesn't get thru POST and there are no error beeps. MB appears to already have the latest BIOS. [EDIT]One 256Mb stick of 266 DDR in the slot.[/EDIT] What's going on?

Also, the label on the CPU says AXDC2400DKV3C, which looks like a 2400+ alright to me, but CPUID and AMD's cpuinfo identify it as an 1800+. Don't know if that's relevant.

Any help mucho appreciated!

 

[meganox]

Just had another go, set the switches and cleared CMOS and this time I got an error saying the BIOS had failed checksum. Seems to me like I may have a faulty board? [EDIT]Or, as a friend has pointed out, I shouldn't buy cheap generic RAM?[/EDIT]