This has been happening since you bought it? You should have perhaps replaced it? After the fresh install what driver did you use? The one from Xenarc website? There's also drivers at the manufacturer website here.
If not, what has changed? If nothing, maybe it's hardware failure, maybe you could buy another TS (~$70 I'm afraid)?
Have you installed in the dash? Maybe it's close to the A/C ducts vents, running hot in the winter?
If it's not in the dash, maybe some internal heat issues, after 30min, something is triggering this. Have you try plugging and unplugging it, perhaps to a different usb port?