Never happened to me. I suppose what's happening here is that the driver wants his rightful place in the queue which you're denying him by being in his spot (which he paid for with his road tax). Not willing to make a fuss about it, but wanting to assert his rights, he just takes what's rightfully his by nipping in front of you. He's doing you a favour by teaching you the lesson nicely with no yelling or cursing.

Hopefully no one fails to spot that I'm being sarcastic.