Hello,The message "Phone Trouble" is seen on the keypad LCD and heard as announcement when the Incoming Telephone Line, but the line is working and I can do calls. I also have a UCM/GSM4 and everytimes the alarm calls are doing by GMS instead of line. If I check the “Ignore Line Cut” option I leave to have the message "Phone Trouble" but the call continues to be made of the GSM. The line voltage is only 37V. So, is it a problem with the line or with the Comfort?