I remember something on here a while back about a 'knocking' noise on these forks.

They are brand new 2009 air U Turn 110-140.

At 110 they make a knocking noise (doesnt seem to effect performance) but after you click up the travel a few notches it goes away.

Anyone know if its a problem and I should send them back?

I found with my u-turn Pikes you could end up with the u-turn 'between clicks' and it would make a knocking sound. Clicking it either way would sort it out though.

i've got some '08 revs, 100 – 130mm. and at either end they're fine, but anywhere in the middle, there's a little knocking noise. They work fine and its not a big scary noise, just a little knocking.
I think i read that this isnt uncommon, and i've since managed to ignore it.