You have emailed Kerio's tech support before posting here right? That would be the first place to start. What did they say?
The synch....or not synching as it is in Entourage is normal. There is no way to tell it when to synch which is stupid. Read the help and or the entourage / exchange documents up on
http://www.microsoft.com/mac. The have the specifics for when they sync.