has anyone else but me had display trouble with these phones. the display shoots of a bunch of nonsense symbols. sometimes unpluging the phone works and sometimes not and they need to go to aztec. i had two places with the problem last week. brought in the phones and put them on my system and both worked fine. today i took them back and one worked fine and the other wouldnt show the display- that was the origional problem with this one. well i brought it back and pluged it into my ksu and it is working again. the loaner phone at the location is also working fine in the same jack where this one wont work. any ideas on these eratic displays. thanks dave