I've come up with an idea how to fix this. Simcard tray for n9 for about 10 times more expensive than that for lumia 800 but lumia's too short and n9 doesn't see the sim card. So I bought a simcard tray for lumia 800 and switched the plates inside so that the plate where simcard is hold is from n9 but the cover is from lumia 800. Works like charm.