Hi Remon,
this is likely due to the AP125 doing MTU discovery by sending > 1500 byte MTU packets. You can check if the errors increment on the switch port at the same this as this counter from "show ap debug system-stats ap-name <ap>"
MTU Discovery
-------------
Probes Responses Last Sent Last Rcvd
------ --------- --------- ---------
5533 2766 332106 332045
Switch MTU, Update sent time, Ack receive time, Current time (Time in seconds since AP booted)
1500 277477 277477 332142
you can stop it from doing this by setting the "SAP MTU" in the AP system profile, but otherwise it is harmless assuming the two are incrementing together.
regards
-jeff