Here's a scenario we discovered on our 3560's.
IOS Version 12.2(25)SEB4
The power setting on the port is power inline auto:
1. Non PoE device is plugged into the port (PC)
2. Non PoE device is unplugged
3. Cisco 7961 IP Phone is plugged in
The phone will not power on.
To get the phone to power on, I change the port to power inline never, then power inline auto. If I unplug the phone and plug a non PoE device back in, the behavior returns.
Is this functioning as designed or is there a fix?
This is a BUG with the IOS version that you are running the 3560 switch.
The Bug ID is CSCsc10999
Problem: Switch does not power PD when non-PD device previously plugged into port
The resolution is to upgrade the switch to atleast Upgrade to 12.2.25SED or higher.
HTH,Please rate if it does.