Looks like it's indicating an issue writing something to a MAC address, but that MAC address range is reserved for multicast traffic, which I have no idea why a 3300 would be sending. What version chassis is it? There's certain vintages of the MXE-II (part numbers 50005090 and 50006211, specifically) that are known for having issues with the MIPS processor (runs the onboard L2 switch), maybe this is pointing to an issue with that?