Hmmm... uIP-tool doesn't work on my TT with a Netusbee-lite.
I thought, after looking at the source, that the timing loops for 1ms, 10ms and 100ms delays might be the issue as it might be trying to read the device too quickly. (uIP-tool doesn't get a MAC address even though all other diagnostic programs for the device show no problem.)
What version are you running?
(uIP-tool works fine with the same Netusbee-lite device on my STE and two of the three other STs I have.)