Well, I have done some more testing at my house.
I have TSU9600 connecting to RFX9600 via WAP.
RFX9600 is in DHCP.
TSU9600 is fixed IP.
Network is set to 24hours.
Using WEP64.
Fixed, single channel wireless settings.
All I have programmed in the controller are DirecTV (RS), Denon AVR(RS), and HTPC (IR). No ProntoScript, or 2-way communication at all.
Just like in the house I referenced above, I see that I can issue one command just fine, and when trying to issue second command, the function does not go thru and the busy light stays lit on the RFX9600 for some time.
I have all the latest firmware on both TSU & RFX.

I do have another RFX9600 NIB that I can try to test.
I can also disconnect the WAP from the rest of the network, to make sure its not a network issue.
It seems wiered that two different instalations, using different network hardware, would exibit behavior. (Although both houses use D-Link products. Mine is DIR-655, and client's is DIR-625).

In both cases, the network icon on TSU9600 goes from showing good connection, to dropping it and showing 'connecting' when the RFX9600 is showing busy signal.

I'm wondering how many "network connection" issues that many are reporting, are actually RFX9600 not responding/freezing when it's stuck in busy state?