I didn't hear of that regulation either when I took the train to Sarajevo. Actually I have to doubt whether it exists in this context because if you get on the Zagreb train to Sarajevo it runs all the way through Bosnia and then on to Ploce in Croatia. The point being that you could enter Bosnia on that train, go all the way through the country and then re-enter Croatia on the same train without buying a return ticket.
I would recommend few days somewhere on croatian coast, there are many nice islands like island brac, hvar, vis,...if you like to party a lot then hvar and pag (town novalja)...and definately visit plitvice lakes...skip Zagreb (I live in zagreb and there is nothing to see during the summer).
And do not worry about our relationship with srbs, it is always hard after war...but things are changing in positive way...and almost every country has some issues with neighbours...for now croatia is safe to visit
I wish you pleasant and safe trip!
all those suggestions make me want to go there right now!!
one thing, in slovenia, don't forget the caves - they're amazing. and as for the political thing between some countries in that area...as nikolina said, it's better now, but you'll also be better off, not being from the vicinity in either case. so don't worry..there's lots to see and shouldn't be missed!!
Yes, the Slovenian caves are one of the must sees off my trip around Eastern Europe. Does anyone happen to know more unique must sees in the countries I'm visiting? (Apart from the Old New Bridge in Mostar )