Found this ...

by JayDP111 - 1/2/13 11:44 AM

In Reply to: 1. The best format to store it in is. by R. Proffitt Moderator

I found this, thx for the suggestion.
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If the DVD authoring program does not accept the MTS file, try renaming it with an MPG file extension. Most digital videos that contain an MPEG-2 data stream are distributed as MPG files. The format is more widely recognized than MTS.
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(And I get the impression that DVD Flick is no longer maintained by the author?
I could be wrong, but the DVD Flick forums on the DVD Flick website are closed, inactive, unavailable.)