Neck pain after switch to Resmed N20

Has anyone had neck pain after using a Resmed N20 or Resmed F20 and, if so, what have they found helped?

I ask as the first time I used an N20 with its stiffer straps I woke up with a neck pain. That was over a month ago and I still have the pain despite trying several different pillows, including a CPAP one. It's the sort of sharp achey pain that comes from sleeping in an awkward position; I am, though, unaware of being in such a position and there's a good chance that the pain is completely unrelated to the N20.

I'd like to stick with the N20 as its much more comfortable than the Resmed N10 that it replaced (the straps were getting tatty and the strap velcro no longer held).

It may be as simple as covering the straps....figure it out yourself or go to padacheek.com for strap covers.