Only keys volume work

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Hi

I'm really new to this (noob) but LMMS won't play sounds when for example, I'm in general setting of the TripleOscillator and I increase/decrease vol or pan, crs, fl/fr etc...

Is there a fix for this?
If you are using windows, use SDL as sound-device
else:
please post your:
* OS (+service-pack-ver)
* lmms vers
* hardware specification (ram & soundcard is the most imortant)
* lmms sound device chosen