IP Phones not getting Power from PoE

Hi,
In my network cisco IP phones are not getting power some times from 3750. When I am reloading the switch they are getting power. This happend twice in a month. Please help me resolve this issue. below are the switch IOS details.
(C3750-IPSERVICES-M), Version 12.2(25)SEE2
cisco WS-C3750G-24PS

“flash:c3750-ipservices-mz.122-25.SEE2/c3750ipservices-mz.122-25.SEE2.bin”

If you need any further information please let me know.

All the ports are on default config of Cisco for inline power.

I am pasing one of the port config as well:

interface GigabitEthernet1/0/16
switchport access vlan 90
switchport mode access
switchport voice vlan 50
spanning-tree portfast
end

Eagerly waiting for the reply