The PHONE1 jack on the 202 is actually a 2-line jack. (Intended to support a 2-line phone.) It has PHONE1 on the centre two pins (ie 3 and 4) and PHONE2 on pins 2 and 5. If the cord you have plugged in to the PHONE1 jack has more than 2 conductors going to its pins, try a cord that has conductors to only the middle two pins. My thinking is that if both PHONE1 and PHONE2 signals are getting to the phone it may have some unintentional weak path between them.