Check this bug out CSCdu72626 and you can upgrade to 6.3.3.
Release-note:
When ERRORDETECTION PORTCOUNTERS has been enabled (defaulted to disable) and receive errors occur on port 1/1, a syslog (SYS-4-PORT_ERR) may be received reporting rxTotalDrops on 15/1, instead of 1/1. Some installations may find that the feature has been enabled by the software and will remain enabled after upgrades. This latter issue has been resolved in 6.3(1) for a fresh install.
If the syslog is seen, investigation should be directed towards the first uplink port (1/1 or 2/1) not the port reported in the syslog (15/1 or 16/1).
A SHOW COUNTERS command will show what errors are occurring. If the only error counter reporting errors is rxTotalDrops, then the most likely cause
is there is a spanning tree blocking VLAN on the uplink port and the drops
that are occurring are CBL drops, which are expected. If there are other error counters reporting, the cause needs further investigation.
The workaround is to disable ERRORDETECTION PORTCOUNTERS (SET ERRORDETECTION PORTCOUNTERS DISABLE).