CMM micro +AP ---problems

Hi there,
I have 4 AP conected to a CMM, and I keep getting a very weird problem;
2 or 3 times a day, the one AP that I have connected to the CMM stop working.
If I check the status of the CMM, it show that this AP is
operational, but if I try to ping the AP, it is not respond and
all my clientes int this AP are down.Another three AP’s are working at this moment.
Has any one had this type of problem?
If reset “port power control” on CMMmicro, AP begin working.

Ethernet Statistics AP’s --no errors
Statistics CMM -no error, no collisions
CANOPY CMM 2.2 Build 2a Oct 12 2006

Try upgrading all 4 AP’s to 8.2.2

Today i upgrade all my Ap, but my one AP AGAIN STOP WORKING. HELP !!!