If you inadvertently double-click on an imported (usually by reference) graphic, FM looks to the System for the associated application with the file type and opens that file in the application for editing.
You would have to disable the system level association between the filetype (.bmp?) and Paint. How to do this depends uopn thee operating system. In XP, it was easy to do through Windows Explorer (Tools > Options > File Types find the file type and use Advanced settings to remove the association).
In all versions of Windows, you could use a command window with thee "assoc" program to change this. Type "HELP assoc" for details on how to use this.