I have a strange problem with random phones at random times going off hook by themselves and making a long tone until the user picks up the handset and hangs it back up. I have been keeping record of the different phones doing this and they are not tied to a specific card. So, I don't think it is a particular DTIB card going out. I have several different types of phones on the system: 12&24btn Infinite/display and non-display modles plus 30btn LKD display phones. This is an XTS system Eng. Ver3.50.2-3FE3. Any suggestions on troubleshooting this issue would be greatly appreciated. Thanks,

That's No moon, its a space station!