Alright, we'll have to see if we can reproduce this.  When you say it slows down after a few hours, are you working in the Preset Lists screen or the Presets screen leading up to it slowing down?  And if you're working in Preset Lists for example, how many preset lists have you created?  If you're working in Presets, roughly how many user presets would you say you've created?  I'm just wondering whether there's something about your user data that could be affecting the app's performance…