Sorry Dusan I can't understand your post at all. are you saying the midi track starts to play but then the built in styles on the Audya turn on?
If you have had to re-install OS3 it makes me wonder if you are not having the same problem as others we read about here:
http://forums.ketronmusic.co.uk/viewtopic.php?f=3&t=688 My Audya just 'works' perfectly in a MIDI environment so it has to be:
1) something your doing wrong
2) something you (or you retailer) has already done wrong (like the OS update thing)
3) something wrong with your keyboard.
4) something wrong with your software.
Don't let it frustrate you or complain about it here, just ask the shop you brought the Audya from for help, that's what they are there for. If they can't help they should ask their distributor, if the distributor can't help they should ask the factory...its how a support system works.
And do the same with the software package.