just tried to move to real work and put the board into my lab. There I connected the board to a USB HUB and … nothing.
After connecting to the PC directly it works.
This is a really big constraint, because there were very few USB sockets on current PCs and mounted at strange places, so it will be MUCH more EASYER to use a hub.
Have you tested with any other device connected to that hub, for example move the keyboard over to the hub?
Most likely this is power related. Is it a powered hub, what device are we talking about (your G400 or EMX DevSys, or others?) and what peripherals are attached? Many older PC USB ports are woeful at providing enough power to run anything more than the standard device with nothing attached…
On laptop, works directly, because I used USB 2.0 port, high current out (also used to load mobile phones …)
PC in my lab: Front socket, direct connection works, socket is USB 3.0
PC in my lab, but USB 3.0 hub: USB sticks working, but EMX DevSys only with external power supply attached to the hub. As I currently carry out some renovation to my working places, this supply was accidently off, sorry.
Facit: EMX DevSys is good on USB 3.0 / Win7 pro directly, or by external powerd hub.