Xenith Zero Client & Mouse Support, and USB Drives

I'm testing a few of the Wyse products out for utilization with our Citrix environtment and the Xenith Zero Client is really a rockstar... my only complaint at this point is that the mouse doesn't support my 4th and 5th buttons...

Is there any way to get those working? I miss my forward/back buttons...

The other issue, and I'm not sure this one is fixable, but we are needing USB drives to work for some of our end users... so for the Xenith to be a true winner it needs to support USB thumb drives... thus far I'm not able to get that working either, and I believe it's just a matter of them not being supported, am I correct?

Thanks,

Willa