Recently I have copied all my video tapes (camera) to DVD-R as they contain precious memories; using a Panasonic DMR-E20
those DVD-R play very well on the DMR-E20 , my Panasonic DVD RA80
and my family's Panasonic A360 and Thomson 220; so far so good !
my family wanted a copy : so I've put the DVD-R's on my Mac and burned a copy using Toast 5.2 - DVD copy command - on the Pioneer 103

Again: those computer copies play very well on my DMR E-20 as well as on the Panasonic RA80
To my surprise: both the panasonic A360 and the Thomson 220 cannot handle the computer copies; I suppose the copies should be an exact match of the original DVD-R
my computer: Mac G4-400 latest OSX toast 5.2
note: the computer does not recognise the DMR E20 files (VRO) but making copies with Toast (DVD copy) remains possible)
Does anyone have an explanation/solution ?