Hey, that sounds like me! When things that a bit demanding for me and I concentrate really hard, my tongue sticks out. Carola, do you remember at the Robert Clinic, he kept telling me to relax my lips!!!

:O
Seriously though, I have actually only just read about this in Podhajsky's Complete Training of Horse & Rider. And I just need to go back and review it, and I'll post something about what he said. Stay tuned....