Golf MK5 Blower problem

[aerofish]

Hi.
I have just started having a problem.
My blowers stop blowing air in any direction after about 10 mins.
If i go back to the car after a while the air flow returns and then stops again after a while.
This is on all speeds and directions. It still makes all the sounds of the blower working just no air???

Any ideas appriciated.
:D
VW Golf MK5 Air Conditioning, 'Climatic' semi-automatic control