Hi Andreas,
Sorry to hea about your continued troubles. The USB 3.0 card you mention (Inateck KTU3FR-4P) is not a card that we have tested in house so there could of course be some incompatibility problem. I do not know the brand of your previous card, and there is of course the risk that that card also is incompatible (double unlucky). Have you tried with one of the USB 3.0 cards that we recommend, or on a computer with native USB 3.0?
Since you have already tried with updated drivers, it seems like that is not the problem. My guess is that either you have been unlucky with both of your selected cards or there may be some malfunction with the device (eyetracker or cable) that you have. It would be one of very few hardware malfunctions reported but you may of course be unlucky in that respect.
We are ordering the USB card you are using so that our Q/A team can test it in house, but the result from that will take a little time.
In the meantime I can really only suggest three things, either wait for our test of your USB 3 card, or try your device with one of our recommeded cards (because then it should work no problem if the hardware is ok) or contact our support for a replacement unit. However if it turns out to still be something about the USB card, the exchange will not help.