We have an IP Office 406 with a few addon modules for analog and additional digital ports. Everything has worked well for some time. However, yesterday when one user attempted to dial another users extension (6701 dialed 6719), what happened was rather strange. The user at ext 6719 picked up the phone but could not be heard. Instead, the 6701 user heard a conversation one of our customer service representatives (ext 7376) was having with a customer. Neither the customer nor the rep could heard either of the other two parties (6701 or 6719). So we figured a big glitch in the config. So we tried the same thing again. Exact same thing happened. This has happened once before when a different user called 6719. The "fix" was to unplug 6719 phone and voila... It has not happened in 8 months. Good luck with this one... If you have input, I would love to hear it