ok, booked up flights to Zagreb. Plan is to go to the lakes on your advice Red Frog.
Then going to get the night train to Split and end the visit in Dubrovnik. All these places look pretty good and I guess won't be too expensive to eat and drink at!
The Plitvice lakes were stunning. A friend and I went in October and we had the place to ourselves. It might be a bit busy in June. The bus from Zagreb was quick, comfotable and cheap and the driver was happy to tell us where to get off etc.
[url width=720 height=540]http://i3.photobucket.com/albums/y98/trebblej82/Plitvice.jpg[/url]