This is a known limitation of the report. The problem is the etherswitch modules as well as the chassis-based 3750s all share the same sysObjectID, and the report keys off of that ID. The reason for this is that all of these switches can be stacked together to form a virtual chassis. You can assign a unique sysObjectID to each type of device using the command:
no snmp-server sysobjectid type stack
But that cannot be done if the 3750s/modules are in a stack, and may cause other problems with management applications which expect the default stack-based sysObjectID.