Hi!
Earlier, when I imported a midi drum-loop e g for Battery the midi-file contained all the different drumsounds. Now when I do the same, the mid file spilts into several ditto, each for the specific drum part (crash, kick, cow bell and so forth). How do I prevent that behaviour? I want just on midi file for the whole drum kit.

You have one MIDI file for one drum kit. It doesn't matter if its split or not. All that matters is where each track is outputting to. If its more than one use ctrl to set the outs to the in of Battery.
 
However, if you must have only one MIDI track save as a type 0 MIDI file. Type 1 will give you a track per each instrument. 

Thanks John! I'll save it as type 0 then. Most appreciated.
Greetings
Mikael