Reed adjustment on Northumbrian small pipes

A friend of mine loaned me a set of NSP’s. She bought them new and could not get the drones or chanter to sound.
I blocked off (not permanent) the drone ends to work on the chanter.
I squeezed the sides of the reed to see if I could get the thing to play.
I have been able to get a couple of tunes out of the chanter as it is simple enough to finger, but the problem is the reed keeps blocking, or stopping for want of a better word. I have tried adjusting the amount of pressure on the bag (more/less etc) but the reed will just stop sounding after a few bars of any tune.
Any tips on what to do here people?
The pipes sound great, quiet but such a nice sound.
Cheers,
Tom.

Maybe you can get some hints here.

http://chiffboard.mati.ca/viewtopic.php?t=48741

The vids are Colin Rosss making NSP chanter reeds.

David

Thanks BigDavy,
The youtube video links are great, the fourth one in the series is the one that really helped me.
I will try out a few of the little tips from the clips and let you know how I get on.
Cheers,
Tom.