Is there a way to change the Change the Current Username on Flashed EVO 4G ?

I just purchased a EVO 4G that was already flashed to cricket, but after I changed it to my phone number and paid the $15, the Web does not work, nor does Market or VoiceMail. I cant get the manual programming to work either.
Dialing "#626*" OR "##626*" Tells me that the call can't be completed as dialed.
Also, when I go to link the phone through the USB, it identifies the phone on the market place as Device LGE LG-LW690. I cannot install anything from either AppBrain or the market.

Can I fix these problems without reflashing the phone ? How can I tell which flash ROMs were used etc.. etc..

PHONE INFO:
Android 2.3.3
PRI version 2.15_003
PRL 35213


Phone Model PC36100


Device LGE LG-LW690


I'm new to this, so any suggestions or ideas welcomed.