Maybe the title of this thread is too specific. I experience the same delays as well in file open dialogs for such "richer" directories (for instance with the Mirage picture viewer from Garage, which is in Python). There seem to be some system calls used by filemanager and such dialogs to explore directory content. The lag may result from the analysis of file type and/or assigment of icons or handlers for opening the file under inspection or whatever. The truth is in the code, so either a developer could give an answer or one has to study the APIs. For me it would be a tremendous improvement to speed up these dialogs and in particular the filemanager on "rich" directories. It's a real show stopper when I demonstrate my wonderful N800 to others by navigating through my pics collection, but then I have to wait 5 seconds before I can enter another folder for the first time. I'm thinking of filing a bug in Maemo's bugzilla.