oozenoz

Sounds to me like you may be picking up interference.

When they reran the cabling, did they put it into conduit or perhaps even move it to another area of the wall? Is there anything consistent about the time when the phone reboots? Any other equipment in the area that could be running/starting at the time the phone reboots?

Fataldata is right - take the phone from the room, plug it directly into the port you are currently using and monitor it for reboots to isolate the cabling.

__________________
- calvin