doesn't hentai also mean "abnormal" or "sick"? ("sick" as in "I got the flu" not "OMGBOOBIES!!!11oneoneLOLKOLOLOL!!")
I was watching a japanese tv show with english subtitles - i swear I heard "hentai" somewhere in there as the dude went to hospital... and another time when it was used for "weird" or "strange"...