Having 2 different kinds of memory may be part of the problem as they can only go as fast as the slowest set. Double check to see what they are rated for. Not sure what you mean by them going up in 50+ increments. Is that halve a volt or .05v?
the ram goes up to 2.ovolt and they both go at the same speed same timming what i did to get it working a while a go was bring the ht down to 400 and the multiplier to 13x then i brought the fsb to 247 timming @ 4-4-4-14 ant oveclocked @ 3.2ghz