I'm also from Australia so I use PAL. Not UDF has nothing to do with video video type. UDF is the official DVD format. If you burn dvd's as data disks then they'll only play in some set-top players & your computer. Make them UDF & they should play in all that have the ability to play dvd-r disks. Personally I generally trial them out on dvd-rw 1st to make sure they play how I want them to. Two speed is fine!

What brand of set-top player do you have? What brand & model of burner? If you have a mac then probably it will be a Pioneer. I bought mine separately from the computer. I also specially hunted thru dvd set-top players to make sure the one I chose would play ALL types of dvd & cd; ie: dvd-r, dvd-rw, dvd+r, dvd+rw, vcd, svcd, audio dvd, etc.