Hello
You are running a very old release of the FWSM module; the first recommendation would be to update to the latest release within your train.
You are currently running 4.0(4) and I think 4.0(14) is the latest sub-release in that major release.
Also how are you sending traffic to the FWSM? Can you please post the configuration of the host switch (Vlan groups etc.)
Regards
Farrukh