have you checked Comm Manager/Settings/Phone/Roaming
Set Data Roam Guard to Never Ask and Allow Roaming.
I found my problem also, after flashing to the newer rom.
I accidentally changed my registry setting:
HKLM\Software\OEM\PhoneSetting\NetworkService
My ItemValue2 should be = 4 ( I had it changed to 2)
--
(string values)
ItemName1=Sprint Only
ItemName2=Automatic
ItemName3=Roaming
(DWORD)
ItemValue1=1
ItemValue2=4
ItemValue3=3