request not understood

I unlocked a virgin mobile 3310 last night, so that my wife could put her cellnet sim in it. the unlocking worked fine (had to use both codes), but my wife cannot dial out. she can get incoming calls, and send txt, but when she dials out a voice call, she gets the message "request not understood". my O2 sim works in the unlocked phone, and the cellnet sim works in my t68 (she can't use my 68 tho, coz the battery dies after 6 hours). the cellnet sim worked worked in my wife's 3310 until she spilt coke on the phone, and broke the phone.

any ideas?