The MWI (message waiting indicator) light will not turn on when there is a voicemail left on that extension. We have 40 phones. They are all 3COM 3102 Business Phones. All of our phones, with the exception of 5 of them, operate without issue. The 5 in question all suffer from the same issue with the MWI not lighting up. Funny thing is, they all used to work at one time. The MWI will blink on and off when the phone is ringing, so I know the light hasn't gone bad. I have already tried deleting a phone from the system and then reconfiguring it as a new telephone to see if this would solve the problem. It did solve the problem on one of the phones. But I still have 5 phones that still don't light up their MWI. Any thoughts?