Creaky doors!

Hi all

I've got an annoying little problem with a 2006 Mk2 LX and I was wondering
whether anyone else had the same....

My drivers' and passenger doors both kind of "creak" all the time, near
where the bottom of the window "meets" the plastic of the door - near to the
door handle on the inside. The noise is like a little plastic "ticking",
that as its near your ear on the drivers side, annoys the hell out of you
when you tune into it. Oddly enough it goes away if I slightly pull the
door plastics just half in inch or so away from the door.....

I've looked inside the doors and can't see anything loose in there, so I'm a
bit at a loss what to do - its driving me mad!

Has anyone else got the same problem?