I have a multiple 3560G-48PS switches supporting IP phones (non-Cisco.) About once a week I get a call from a user who's phone dies (no power), and the fix is to go into the port and do a shut/no-shut. Once I bounce the port the phone draws power again and everything goes back to normal.
If I do a 'show int' the port is down/down, but if I do a 'show power inline' it shows that the port is drawing power.
I have 30 remote offices and have had the issue in most of them. They're all running 12.2.25-SEE or SEE2 IP base. Theres plenty of power remaining on the switch (via 'show power inline')so I know its not that.
I'm fairly sure that its not the user mucking around with the wall jack; I've had reports that the phone just dies in the middle of a conversation, and also when its just sitting there. There's no rhyme or reason to it.
Unplugging from the walljack has no effect, switching phones has no effect, etc. There's nothing in the logs, either.