Q: updated to itunes. 9.2 & now none of my music library files 'can b found'?

updated to 9.2 itunes-quicktime and 5.0 safari. Went to play music in library and every song has exclamation point by it, when click song msg reads 'cannot locate music file'. Have had music library on 3 different ipods over the years & have always updated when asked, & never had trouble playing any of library files. Since syncing ipod while downloading update, now ipod wont play any song either. Anyone else have this issue? Is itunes doing this now so need to repurchase all of my songs in updated 9.2 format? If so, they lost my business immediately.