Curve 8520 no uma

[dragid10]

alright so unlocked att blackberry curve 8520. i've been trying to get uma for a while. i reloaded t mobile os 5. i got to the e-screen and unlocked the uma option and rebooted. i did everything correct. but when i turn on wifi there is no uma!!! it just says at edge or when wifi only it turns the mobile network off. i'm really stuck here and don't know what else to do..... can somebody please help me!. also if it helps there is a dash next to my wifi but wifi works perfectly im able to surv opera mini and native browser. and also in wifi options i do wifi diagnostics and under UMA the only thing with an x is connection. then under it says "Status: isp error. DNS server cannot be reached."