I recently put in an old 5770 along with my GTX 660 since I was only getting about 68 Mh/s, the 5770 alone gets about 380 Mh/s.
With any miner I use, CG, Phoenix, GUIM, the 5770 is shown mining at its normal 380 Mh/s but no shares are ever accepted.

I've been scouring forums for the past days and found a few people who had the same problem but I never found an answer.
I spent about $160 for a new PSU just to run the second card, I could pay that off in just over a month if it could mine that whole time.

Any help at all is appreciated; links, personal experience, anything is great. Thanks!

-dH