In the song editor when you create an instrument pattern (e.g. for TripleOsc) containing notes with detuning automation on it, then the detuning is only working when you move the pattern to very first bar (position 0 in the song).
Easy to reproduce with the attached LMMS project containing only a instrument track with three patterns - each of them with note detuning automation.
Tested with LMMS 0.4.90 (from git) and 0.4.10 from Ubuntu ppa
loving LMMS and using it a lot - unfortunately my knowledge of C++ and Qt is nearly zero -- Andi