Cisco Catalyst Switches not reporting macs/ip's on All ports in switchport mapper

Greetings!

My network infrastructure is set up in the following way:

-pfSense Firewall (Router duties)
--Cisco Catalyst 3560G-24 (Core L3 switch)
---Cisco Catalyst 3500-24
---Cisco Catlayst 3550-24
---Cisco Catalyst 3550-24
---Cisco Catalyst 3560G-48
---Cisco Catalyst 3560G-24
---Cisco Catalyst 2950-24
--Cisco Catalyst 2950-24
---Netgear ProSafe GS-108T (x10)

All are configured with SNMP communities (RO & RW) and have been added to various tools in OpUtils including the switch port mapper. I am having a problem where all of the devices except the 3550's are correctly reporting what is connected on their ports. This equipment is all on the same subnet and >80% of the active ports are showing mac-addresses and IPs. Is there something different about the 3550's where they would not report the same way? Help would be greatly apprediated.