I have brand new 7941 which when I jiggle the RJ45 cable, it reboots. I tried different 7941, different cables and all of them do the same thing. I tried 2 different POE switches and same problem.
s72033-psv-mz.122-17d.SXB2.bin on WS-X6148-GE-TX
s72033-pk9sv-mz.122-17d.SXB11.bin on WS-X6148-GE-TX
Callmanager version 4.2.3sr1 with load Jar41sccp.8-2-2ES4.sbn.
7941 Hardware Revision is 68-2518-02 E0
I remember a couple of years ago back the 79xx had the same problem and there was a FN out on it.