Topic: Reciever in usb extension not working to good

Im working in a foleystudio and using the Tranzport when im working alone. We have the computers in a machineroom and im using a Gefen extender for the usb and the screens (Cat5 5500R).
The Tranzport have never worked flawless, i have to give it some time and the lights on it doesnt always show what is pressed (like the record button etc) but its still been workable.
Some weeks ago some strange thing start to happen, if i have the tranzport on my sound out from Pro Tools have alot of distortion, as soon as i put the tranzport in sleep mode (not disconnect it, just press battery + backlight button) it sounds good again. So now every time i have done a recording and wanna listen to it i have to remember to  put it in sleepmode :(

If i connect the reciever directly to the Macs usb it works fine, so the problem is in the extender. I have tried another extender but its the same problem.

So anyone else with the same problem? Or know what i can do, is there a great usb extender out there i can buy and count on that its working better?!