USB-UIRT stops responding

For no apparent reason, USB-UIRT stops responding every now and then (once or twice a week). The only way to reactivate it is to unplug it from the USB port and plug it back in...
When that happened, most of the time I was watching TV. Unable to change channels with my remote, I closed Girder and reopened it. At that time, a message appeared on the screen saying that USB-UIRT was not responding. That's when I had to unplug it from the USB port and plug it back in, as that was the only way to reactivate the USB-UIRT...
Any idea about what could be the cause of that?
When that happened, most of the time I was watching TV. Unable to change channels with my remote, I closed Girder and reopened it. At that time, a message appeared on the screen saying that USB-UIRT was not responding. That's when I had to unplug it from the USB port and plug it back in, as that was the only way to reactivate the USB-UIRT...
Any idea about what could be the cause of that?