Why does my persian piss all over my house?

i just got a baby persian a few weeks back and since she was so tiny and i have a couple other dogs and cats i kept her in my room and got her own litter box and she was fine and used it but now i cant get her to go in her cat genie(you know that freaky lookin toilet litter box that flushes) so last night i got her a regular litter box again but she wont go in that anymore! a few people told me persians dont like to live in the same household as other animals and they get pissed and piss and crap everywhere but i dont know if thats 100% true... so i dont know, just wondering if anyone knew anything about persians and why she is doing this.....