I've taken off a few bits on my 130TDI to get to the cabin filter, under the filter is the air intake.  When the engine is running and the air con is on (NOT in recirc mode) the flap is closed all the time - whether it's on recirc, HI, LOW or whatever.  Should it be like this?  I was under the basic idea that it would be open all the time unless I pressed the recirc button. 

Anyone with any idea about this?

Thanks.

Sounds like there could be a problem there,

Im under the bonnet this weekend so i'll whip my cabin filter out and see what happens in re-circ/fresh air modes.

Might be a different set up as mine's a little older but ill see what i can find.

OK, thanks for that.  It might be slightly different as mine's dual zone climate, but I expect the basic set-up is very similar.