Our bike club from work went there last summer although I didn't join them.
They did a five day tour and had a great time. I think they got some tips from here:
http://www.mtbture.com/
and downloaded topographical maps here:
http://mapy.mk.cvut.cz/data/Slovinsk...nia/Slovinsko/
If you are interested, I will ask if they mind me sending you a copy of their report, or posting it here (their webpage is for internal access only).
Bron