It's late, and I should be sleeping - so this will be quick.
There are number of techniques to block or counter the muay thai round kick. The video below outlines only a handful. We shot this in one take over the weekend, so pardon the slop in my technique, but it will give you some ideas of how you can use your angles to completely negate the muay thai round kick.
I saw one of your videos over at somaserious.com and thought I would venture over.
Excellent content, I really enjoyed checking out a couple of your videos. Very crisp, quick techniques - which I always enjoy seeing.
Keep up the good work!