I've tried using imageburn, and the burn a dvd option was greyed-out (not available) due to the file format.
I'd also tried burning one that had been saved in .avi, but that still would not play.
I've had Nero installed in the past, and might try that again.
But is unimportant right now, except in respect to the OP's question, as a friend who does this sort of thing for a living has offered to do it for us.
TY.