Pad not responsive

Hi,
A few months ago my firmware was updated by the local supplier. Since then, a weird phenomenon occurs - sometimes, during music play, the pad turns non-responsive, and the music keeps playing until battery is dead.
Did it occur to you ? how can I downgrade my firmware one notch ?

Thanks

Did you check the "hold" switch?
The up/downgrade procedure is explained in the FAQ. Make sure to use the right firmware for your model (TP/SP/SL/TS).

As this is not mentioned in the FAQ (or I am just too dumb to see it), these are the firmwares you should use for the corresponding versions:
SP
SL
TS