Hi Torgeir,
Could you please share the FW version running on your MC7304?
If the FW version running is < 5.5.22.x, suspect it was a known issue related to SMSC (+CSCA) and already corrected, please see:
http://source.sierrawireless.com/resources/airprime/software/release_notes/mc73xx_fw_build4206_release_notes
To resolve this issue, please try below options:
a) upgrade to latest FW (>= 5.5.22.0)
b) re-configure the SMSC without the “+” sign, i.e. AT+CSCA=“4790002100” for your Telenor SIM.
Hope it helps.
Thx