@stevealb, @nefast --
I've never noticed that, so could you clarify? How do you open those message lists?
From the main window (account list) by tapping a folder? Launching the app from a widget that points to a folder?
Does the message list never load at all (if you wait, say 15-30 seconds)?
Can you try Menu -> Compact the message store in the main window, to optimize the database, abd see if this fixes it?