The solution is essentially the same. Close all windows, drag the columns to the size you want (note that it will NOT preserve individually sized columns, unfortunately, but it seems to use the average size), and close the window. You may have to do this more than once depending on how you open windows (Command-N, or open a folder via the Dock, or opening a folder on the Desktop).
This will both preserve the size of the window and the average size of the columns, as well as the view its in.
-- simX!