Yes I tried a CTG 25ft cat6 cable earlier but that was also from the S750 switch, I currently have it connected to the S591. From reading the Amazon reviews there are others with connectivity issues that seem to stem from ver. 1.0R. I think for now I've seen enough and need to swap that back out for the Qnap, I want to give this thing to a friend who works in IT to test it but he is more on the end of managing the servers but he also has a nice setup in his basement with a lot more extensive knowlege of the inner workings of a network than I do especially troubleshooting over the network. When I worked in IT it was mostly providing end user support, installing switches, APs, installing LCD projectors, network troubleshooting, mostly the physical layer, I've replaced tons of RJ45 keystones due to bent pins.
I just troubleshooted my first L3 switch two weeks ago that partially died from a surge....that was fun while 12 users were basically sitting on their hands waiting.