Want to try Tether again!

A month or so ago, I tried to get Tether running under Wine on Linux without success. My trial copy expired before I got XP installed in VirtualBox to test that. I now have XP running under Virtual Box and want to try Tether again. I downloaded the Windows version and it installed OK. However, on my BB, Tether insists on a registration code. Can I get another trial code to try this configuration.

Thanks!
Norm