Hi air_guard....
There is no voltage control setting available on the actual graphics card, however, it does have a minimum voltage requirement to be delivered by the MB (value escapes me right now) that if not present, or it drops below that value, the system will HANG solid. When the GeForce type cards first came out, it was a very big discussion amongst users on CL newsgroups and there was some testing that revealed that Abit MB's tended to underpower the GeForce cards. You'll notice that the newer 3DFX cards even come with their own dedicated power supply.
I would suggest you try two things, if available to you.
First, borrow a 300 watt power supply and re-run your testing. This can boost the AGP slot voltage slightly on Abit boards, although by design it really shouldn't, but apparently it does in some cases enough to solve the problem.
Second (last resort), try a different MB.
Your problem is NOT Aces High software, that much I can gurantee you.
Regards,
Badger