I've a nasty feeling that this is a symptom of your (newly enlarged) database taking up so much of the player's music cache, that there's none left for actual music cache data. Do you have a "ReserveCache" setting? If so, reduce it by at least 17. (If you don't know whether you have one, then you don't.)

The music cache is particularly small on Mark 1 players (which of course have only 8MB RAM altogether rather than the 12 or 16 of later versions). If you've hit its limit then there's not a lot you can do except slim down your music collection.

Peter