I'm currently going through the same thing. My little enchi had some bubbles coming out if his mouth with his tongue (not his nose) when he threw a hissy fit - he loves to hiss at me whenever I open his tub.

When I opened his mouth he only had a few bubbles in the back of his throat. I took him to the vet and we are currently treating him for a RI. He had no other signs of a RI like yours, but it's always better safe than sorry. I bumped up my temps and he's about half way through the antibiotics and I haven't seen any more bubbles.

I would definitely take him to a GOOD reptile vet. Also, just because someone will see exotics does not make them a good reptile vet. When I only had two snakes I took them to the same place I take my dog and I will never do that again. They said they knew about snakes, but they really didn't. I eventually found a great vet and he's the one I go to now.