Late collisions have occurred on the Ethernet or Fast Ethernet interface. When a collision
is detected by a station after it has sent the 512th bit of its frame, it is counted as a
late collision.
Recommended Action: If the interface is a Fast Ethernet interface, verify that both peers
are in the same duplex mode. For regular Ethernet, the system should recover. No action is
required.
Try this link:
http://www.cisco.com/en/US/products/hw/modules/ps2033/products_tech_note09186a008009446d.shtml