Exporting to DVD disc

I am running FotoMagico v5.3 and am a new user. I love the software but I am having great difficulty Exporting the slideshow to DVD using iDVD. I appreciate that any problems I have with iDVD I should address to Apple, but it is working just fine for slide shows created from within iPhoto.
When I export a simple sample slideshow and select DVD, iDVD is launched as it should, I insert a disc which is erased OK but during the process, I keep getting an error message saying ‘Error during movie encoding’.

As I said, all works fine if I use iPhoto to create the slide show, but can’t export to DVD from Fotomagico. Any thought as to how to overcome this please?