Really? I'm using four RM850s powering two Ants each overclocked to 375, and they all are running flawlessly.
I've used the CX750 to run two Ants, RM850 to run two Ants, Antec HCG-900 to power two Ants, EVGA 1300G2 to power three Ants, and Rosewill RBR1000-M to power two Ants. I really haven't had a bad experience powering Ants.
The only PSU I was a bit uncomfortable running two Ants with was the CX750 because it was drawing 850 Watts at the wall, but the PSU worked for a week or two until I was able to replace it with a better PSU.
In my experience, Ants aren't that picky about which power supply you use as long as it's not a complete piece of crap.
That's interesting, I have to do some more testing then for sure, to see if something else is wrong. I have some various PSUs, including a few CX750 but have not dared to try 2 x Ant's on those. Are you using US source voltage or EU? Although I guess that really shouldn't matter...