I have a intertel 5000 with some remote IP phones. One of the users said that today when he hung up the phone the phone would start playing the greeting over the speaker all by it self. anyone have this happen to them?

It starts playing the greeting of what? The main company greeting? The voicemail box greeting? What stopped the greeting from playing?

It Play's the main greeting. The user said that they would unplug it to stop the message from playing. They would plug it in again and it would play again next time they got off the phone.

Could be that the phone is actually playing your Music on Hold. Have the user press the Infinity key then 313. The LCD screen should read 'Background Music Off'.