changes via itunes not updated on ipod

iPod touch 4g with iOs 5 and iTunes 10.5

hi

after transferring music via itunes to my ipod i can see and delete the tracks in iTunes. i can edit those tracks informations (e.g. Album Name) that are stored on the iPod (via itune/devices/ipod/music) and the changes are shown correctly in iTunes but are not updated on the iPod itself. even after a reconnect the information in iTunes is correct but still not synched to the iPod.