Ah yes, I have not even made a new version as the correction is really so simple, it does not require one. Turns out the problem is caused by the activation of the USB networking interface in the preinit script. This part of the script is NOT necessary for Harmattan startup, only for Nitdroid but it was left there by mistake as I did not realize it might cause trouble. Possible scenario for the problem is that the SIP application searches for the first available network interface and binds itself there. If the USB interface is configured with an address, even when not in RUNNING state, it will still latch to that and not to the GPRS or WLAN interface it should use. Correction: copy the original /sbin/preinit script to /sbin/preinit_harmattan