It's not problem with Colibri. It might be that it has recorded some
noise level which was automatically interpreted as engine run by SeeYou.
If you fly motorless glider, check "Pure glider" in flight properties to
tell SeeYou to ignore noise level.

And remember, SeeYou is a great analisys tool, but it's not a ultimate
claim validation system. It's sometimes wrong in it's automatic guesses
but it does makes claim invalid.

--
Wojtuś