DVD-VR, DVD+VR, & DVD-VIDEO formats

I have a Liteon LVW-5005 recorder, and it is only recently that I found out a bit about there being other different recording formats - I thought the usual differences with DVD video’s was down to DVD-R/RW or DVD+R/RW. In the main I have always used DVD-R discs, generally without problem.
Recently I transferred some video film to DVD-R for a friend and they could not play it on their set-top player, yet I could play it ok. I then tried to make another copy via my PC and it was not recognised on my PC DVD player, but ok on my PC DVD multi recorder. I have tried various software to copy it, but it keeps failing with multiple i/o type errors. Example was - “Cannot copy VTS_01_4: Data error (cyclic redundancy check)”. Looking at the disk it has a name of DVD_VR, and folders VIDEO_RM & VIDEO_TS. Looking at the Liteon manual and the internet, it seems the Liteon always writes to the DVD+VR format regardless of disc… now I arrive at the problem… it seems DVD_VIDEO will play on most settop players and so will DVD+VR, but not DVD-VR. I suppose I should change to DVD+R discs to stand a better chance of them being able to play in the most set-top players.
… I probably haven’t explained this very well, but I was surprised that I had not heard more about this incompatibility with DVD-VR, whereas most people blame the recorder or disks.

Sorry, I have just noticed that ‘imkidd57’ posted a lengthy explanation on this subject just before I raised it.
The only thing missing (my main interest) is the affect of using DVD-R discs which are then formated as DVD+VR by the Liteon LVW-5005 (it formats all discs in the same format).

… The post is ‘The DVD+RW Real Time Video Format…’ in the Phillips DVD Recorder & Player forum…