Maybe you should try turning off the live updating feature of the smart playlists? Seems like every time you start up iTunes if it's trying to update 38 smart playlists that don't really need updating it would take a little time. Just a thought.

I turned off the automatic update for 10 smart lists. iTunes startup time shortened substantially.
But how can I update these list now? I haven't found any commands in the context menu or the application menu to do this.

Ah would that be it, the live updating? Ah.

Still, looks freaky slow if it is live updating in Tiger.

And Jason, I have over 1700 songs. That would be another thing.