I don't even view Joras as some kind of important figure here, I just mentioned him because of the attention he got now and somehow made the conflict about border 'hot topic' again here.
Anyway, I wouldn't really consider certain anti-Croat attitudes here as being part of Serb immigration problem, you can find people who dislike Croats all around Slovenia, the percentage of Serbian immigrant population doesn't really matter, and beside this, I think 'čefurji' are rather pro-Croat in a way of promoting some false 'Balkan brotherhood' cover for their anti-Slovenianism.
However I do agree that most of this anti-Croat attitude is present mostly because of border disputes, which are, to me, only a political game and supported only by politicians on both sides, for their own (sick) agendas.
Personaly, I always had quite positive view of Croatian people, I think it's a shame that those two nations can't be more friendly, considering we're both Catholic nations, quite close culturally (especialy Croats from Slavonia, Medžimurje/Medmurje and Zagorje, my father always told me that we 'Prekmurci' have more in common with 'Medžimurci' than with 'Kranjci'
), didn't have much problems in the past (although there were some - Illyrism, Ustasha occupation of Slovenian land, lack of support during millitary uprisings in 1919 in Slovenia, claiming Prekmurje... - but comparing to conflicts we had with other nations, it's not that big deal), I hope that in future we would have more friendly relationship, after all we had quite simmilar enemies in the past (I'm sure that those are not only enemies of the past, at least not for my nation) - Germanic imperialism, Italian imperialism, Hungarian chauvinism...
P.S.: Just in case to avoid any missunderstandings, me pointing out historical problems we had with Croats is not accusation or something, it's just that - poiting them out, that's all, it's what any nationalist would do.