Thanks Jeff and George,
It's not "really" a corporate firewall - I'm using an IPCop box before my CenturyLink modem (similar to George's smoothwall firewall - mine's running on an old Thinkpad T40 and much better than any Cisco firewall in my book - only because it doesn't cost a grand or more). I've had FTM working in the past through the same firewall (FTM 2010).
By re-configuring the network, I will change the connections in my wiring closet to see if this makes a difference, connecting my PC to the CL modem network (why do I have multiple networks in my house?).
I saw some errors using WireShark referring to IP Checksum failing and it might be related to ip checksum offload (the server NIC does it instead of the CPU). I disabled this function on the card and still see it. Downgraded NIC driver from Intel and same. Will switch over to an onboard NIC after I power cycle and see what happens on a different mfg NIC.
I'm skeptical at this point though as the firewall allows all outbound requests and reply's to requests are allowed back in. I've got guests right now (that's why I'm trying to work on some things...) but when they leave, my bedroom (and closet) are mine again and I can futz around with it.