oc help please

[Corporate Thug]

hey all, i have a p4 1.6A with a gigabyte 8I-EXP mobo. i had the thing oced to 2240Mhz (16X140), avtually it was @ 2.4 at one point. i added new ram and reformatted, resulting in the cpu clock option naturally disabled in the BIOS. i went in and enabled it, but it did not let me post with 16X140, so i tried a more modest stepping for the FSB. for some reason, it does not let me post with anything more than 120 FSB, what is goin on here? btw, the voltage is @ 1.550V with stock cooling. should i bumo it up a notch? any suggestions are deeply appreciated thanx