Yup, happened to me. Training to level 17, I got a light faerie quest, so I went to level 17 before autotrainer was done and thought "it's fine, then it''ll go to level 18"
I had a super bonus and gained 3 levels >_<
or worse, ______ has suddenly gained a level!
FML
fuuuuck..i bet TNT screws with us too by making the odds of +bonuses increase a lot right near the level boundary.