I also have an older DVD player that wouldn't play any recordings recorded on a LiteOn LVW-5005 regardless of media type, i.e. +R/RW and -R/RW. Then I discovered the old player would play all copies of LiteOn recording made by copying the LiteOn recordings on DVD+R/RW with book type set to DVD-ROM using a PC burner. That may be your only solution if yours is the same problem I had.
Nero 6 can easily copy such DVDs simply by creating an ISO image and then burn that image to DVD. Book type setting on the PC can be done for most burners, but the way to set book type varies depending on which burner you have.