I just bought a new Sansa Clip 1G. I found that it regularly freezes at the end of songs. There is no pattern on when it freezes except that it is at the end of the song - it can freeze at the end of a song now, but then next time I play the song it works fine. It happened just after I bought it with .wma files, then I upgraded to the latest firmware and now it happens with .ogg files also. Sometimes it plays one or two songs and freezes, other times it will play several songs before it freezes, but I have not been able to listen to an hour of uninterrupted music. It froze once while listening to the radio, but I have not listened to the radio much.
BTW thanks for the .ogg support.