My Sansa e250R, 2 gigs, froze. Help!
It seems like your E250R is experiencing a temporary system error due to a corrupted song, and needs to be reset.
Try to "Soft Reset" your player, press and hold the "Menu" button until the LCD light and scroll wheel light turn off.
Since the player was probably left on for more than 7 hours (as you indicated), you would need to re-charge the player before proceeding further. Charge it for at least 2-3 hours.
Next, try to format the player to rid of any corruption then re-transfer the songs. If you have subscription songs, then I would suggest to delete the song you last played which caused the error.
I hope this helps. There is another solution for the player, but for now this might actually resolve the issue. Let me know the results. :)