OK, so you don't think me a pompus arse, I too, was having fits two weeks ago with the same exact issue as Motodave.
Two hours at the field, putzing around. I didn't get it, it worked fine at home, several times in fact.

Finally one of the great rc gods at my club walked on over and mentioned the tubing idea.....
DOHH!

Hot tip!

Glad it worked out,