What firmware are you on? And what apps have you been installed on your N900? How much rootf do you have? How many Apps opened? How much music do you have on your eMMC? Those are the questions! -Update to the latest firmware! -Uninstalling all the unstable apps that hogging your CPU and RAM -Clean up your rootf -Close those unstable apps and those memory hog apps -Reboot and let it scan all of your Musics and pictures then start using it, it may take a long time. + Reboot!! These are the answers!