I think it's some sort of sensor failure that it doesn't detect my SD (used to work and test it on my laptop so it's not SD fault) also when i wrote in terminal dmesg | grep mmc0 shows: cover is open ,card is now inaccessible but at the same time the camera cover works and also checked the magnet.it's not a big problem but just want it use as swap and i am not gonna fix it,it's 4 years old n900.so is there anyway to force detect or disable sensor so i can mount and umount manually from terminal or gconf? thanks.