So I read all thru RS's section on Railpasses and I am wondering about Slovenia and Croatia equal one country on the Flexi Saver Pass correct? This isn't loosely interpreted by the conductor right? It will mean the difference between a 4 country pass and a 5 country pass for me. I want to make sure I won't end up in some dispute on a train about borders and whatnot. Also, is there some resource where I can find out what non-typical things the Eurorail pass covers? Ferry Boat tours or bus rides?
You can get the information you are looking for here:
http://www.raileurope.com/rail-tickets-passes/eurail-select-pass/travel-bonuses.html