A new version of DFX is now finished and up on the web site (the Japanese installer should be coming later today). Version 4.0.6 contains a bunch of compatibility fixes for various applications that do things in slightly nonstandard ways that would confuse Default Folder X.
I’ve also added a little code to try and make column view more tolerable in Open and Save dialogs. Default Folder X will now set the default size for columns based on the size of the rightmost column in the last Open or Save dialog you used (not the preview column, but the rightmost column containing a list of files and folders). I know this is still a little “clunky” – it’d be great if I could save and restore the various widths you’ve set for all the columns, or auto-size them to fit the actual contents of the column – but there are limitations in Leopard’s Open and Save dialogs that make those impossible or impractical. So, this change makes it better than it was, but still not as I want it.