Core issue
Cisco Catalyst 67xx modules that run Catalyst OS (CatOS) 8.3.x and 8.4.x sometimes display these error messages in the log:
%SYS-4-SYS_LCPERR4:Module 4: [Log] Rohini 0: packet buffer P2A EEC1: Log only
%SYS-4-SYS_LCPERR4:Module 6: [Log] Rohini 0: packet buffer P2N EEC1: Log only
These messages are log-only, and do not result in a reset of the linecard.
For more information, refer to Cisco bug ID CSCsc48511.
Resolution
This is a software caveat, which is fixed in CatOS 8.5(1) and later versions.
As a workaround, perform a hard reset on the linecard.