can't get past 235 on a8n-e

[bmurray]

I know its a bit dated, but I have been trying to OC my computer for months and have run up against the following problem. I can get the cpu up to 260 with a cpu multiplier of 10, but the memory has to be set to next to lowest value (266), therefore memory running at 266*.66=175. I know the memory can run up to ~235 as I have set the divider at 1:1 (400) and have been able to boot. Usually I run at 220 just to be on safe side. I know I can get my cpu as high as 280 (prime, max heat for 5 min - ~50-51 C). Here's the problem, seems that ideally I should be able to run at 240-250 at a memory divider of 333 (250*.83=207) but my computer will not boot. As a matter of fact if I choose the 333 memory divider I can only achive a speed of ~215. Please please someone help me through this. Why can't I get my core above 215 using the 333 memory divider?

Thanks