ooDialog typically fails silently on errors, if it even bothers to check for error. In general this makes it hard for the typical user to understand what the problem is.
One such case is when the user wants to use a bitmap file. If there is problem opening the file, there is no indication to the user that there is an error, the bitmap just isn't displayed where they expect it to be.
A simple message box stating there is an error opening the XX file would help users understand what the problem is.