Newbie dvd-r recording : pacific 750 player

I have just purchased a nec 2500 dvdrw. Using datasafe 4x R.4.7 media.

I can write these at 4x and they play superbly on my Ronin DVD (see ebuyer) but the Pacific can’t run the discs.

I have tried 2x record and the player (Pacific) plays them but not without the momentary freeze/glitch).

Is this due to the write speed, the media or the software used in recording? (dvd video)

I have used nero 6 for a disc copy. Also tried cheetah dvd.

What is the recommended software for a disc copy (already processed by dvd shrink etc.)