I have the same problem, and havenīt been able to get a straight and forward answer from either "likningskontoret" in Norway, or the super competent people from the Swedish tax society, also called Skattemyndigheterna.
If You donīt have an income in Sweden, You canīt deduct interest rates on Your house in Sweden, according to Skattemyndigheterna.
If You have your economical interestīs in Sweden, You are not eligible to deduct interest rates from Your house in Sweden, when you are doing your tax-declaration in Norway, according to "Likningskontoret".
Thus, it doesnīt help You to have an apartment in Norway, and a house in Sweden, since you are still being considered a "Swede" in an economical sense here in Norway.
I would like to know if anyone have a solution to this implicated problem, since it is very disturbing, and financially troublesome.