I was using a dumb hub at 10mb (no smarts at all, just the wires connected together electronically).
At 100mb I was directly connected with the robot controller connected to our system without any hub or switch with wireshark running on the robot controller.
In neither case was there anything external that could be slowing down our transmissions.
The time difference at the end of the one sequence was the 40 seconds I mentioned previously, the system logged receiving packet 13,875 and sending packet 13,875 at the same time. Wireshark saw Robot controller packet 13,875 and uTasker packet 13,140 at the same time and robot controller packet 13,140 42 seconds previously (at the same time as uTasker packet 12442, robot controller 12442 was from 35 seconds earlier). All of the packets were logged synchronously, from 1 through 13,875 so the uTasker system should have sent them at the same time.