Help - Skipping whole ablums etc

Help,

My Ipod mini (6G) has started to switch itself off. When I switch it back on, it seems to skip though certain songs. They appear in the library, but when I try to listen to them it skips onto the next song, often skipping whole albums. Very annoying! When I update my Ipod in itunes, it re-loads them and I can play them again! until next time it switches itself off.

Any suggestions?