Got a uBlox neo 6m module from a webshop. For a few power cycles, I got a lock, in another, I got time/date etc every second. But after that I am mostly getting garbage from the serial port. In all probability, it seem like a fake unit. The external appearance of the unit (print on the unit/typeface/spacing etc) all look like it is a genuine one. 

Before I remove the can over the device, I want to make sure that it is really fake. Is there a way to find out?