Just switch GPU's and stuff not working

[camodan]

Hey,

I was running a GTX 550Ti until about 3 hours ago when I pluged in the Gigabyte HD7770 I bought for $20 off Craigslist.
Using GUIminer. Card shows up but I get an error everytime I try to start mining. The GTX was load and go just click start and that was all.
I read that the 7770 could do 200 mhash which is 4x better than the 550ti (45mhash).
Cant seem to get this working anyone had this problem?

Cheers,
Dan

[camodan]

Duh typo 5770***