I would do a full backup to SD card or to a PC and then reflash both the Vanilla and EMMC images to clean the phone. Instructions here http://wiki.maemo.org/Updating_the_firmware Once that is done before restoring everything make a phone call. If that works do your restore. If it doesn't you have some hardware problem. As you don't say if skype works over WiFi or GSM, can't say if you have a GSM transmiter problem or not.