i had this problem... twice !!
look
i called the dealer and they told me how to fix it..
unplug the battery for 10 minutes then plug it again then press the breaks for 35 seconds
after that, while pressing the breaks press the e-breaks for 10 seconds..
(( i think these are the right times ))
then the cars computer will restart and the problem will be fixed !!
Had the same problem with my 2006 2.0TDi estate a few weeks ago. Called the RAC man and he did something very similar to the above which fixed the problem...temporarily!
Yesterday it happened again, hence my search for this forum. Fortunately I was at home and could use my wife's car (a 2001 Golf with a conventional handbrake) so was not stuck too badly.
I am now waiting for the RAC again and this time I will watch more closely what he does.
I hope this is not going to be a recurrent problem. From what I have read about the stupid e-brake on B6 Passats I am not so sure.

The first time this problem happened was after a very heavy rainstorm. This time was after jet washing the wheels, so I wonder if water is getting in to the wiring or actuator.
My last car was an '03 B5 TDI 130 estate which never gave me a day of trouble over 150k miles.
You can see I am a fan of VWs, but this car may well change that...