well, first thing to come to mind if you don't want to do the mod is to just try the bios, you can always reflash to your old bios if you don't like it.
another thing is to actually measure the vdimm voltage rather than just take the bios settings for granted. You need to use a multimeter to check. I have heard rumors that the vdimm voltage is not stable on those boards when you get above 3v, but I don't know if that is true or not.