Reply to S4 loop size encoder problems

So, my shiney three week old S4 how has problems.

While practicing just now, my left hand loop size encoder does not respond to rotation at all. The encoder still responds to the push, just not the rotation.

I've already reset all S4 settings, and restarted Traktor as well as setting everything back to default... so presumably I'm looking at a hardware problem?

Any help would be appreicated!

Cheers