No post with ANY mem timing changes. why?

Just installed:

Asus A7V333 rev 1.02 (1005 bios)
2x256MB PC2700 Crucial ram
AMD 2000+

Default mem timings are 2.5-3-6-3, if i make ANY changes to mem timings the machine wont post... ie 2.5-3-5-3, or 2.0-3-6-3...

Infact if i even change the CPU from Optimal to Turbo it wont post... or any FSB increments... Why cant i change a single thing?

Help!
TIA

welcome to the forums, nsuter!

Sounds like you just have some REALLY poor quality memory to me. Your system works at default, but when you tweak the memory at all it won't POST? Try some different sticks of RAM.

You might also look around for a jumper that locks the board to default- a lot of OEM boards used to have this, I don't know if it is still common though.

you can check for a bios update too. perhaps you got some problem with the system setup a newer bios revision can fix..