PPC6700 EV-DO Problem

[PPC6700newbi]

I have a PPC6700 that works fine with internet 1xRTT, texting and MMS with my current provider. The only thing i find odd is whenever i try and get EV-DO i find a tower have full strength but with in a matter of seconds i lose the signal and the EV icon goes away. If i give it a bit of time the EV icon comes back with either 3 bars or full strength but it just gets lost yet again. What settings can i check to see if everything is ok. My current provider is Pocket but since they now merged with cricket i have flashed a EV-DO cricket PRL and i can still make calls and text with MMS but the EV-DO doesnt seem to stay connected. From what i know about cricket EV-DO is available in my area. As a side note when i put EV-DO as the only signal i was able to load my youtube app and the EV-DO did work for like a second until i lost the signal. Any info could be appreciated. Thanks