If I have a 4X spped DVD-RW / DVD-R drive, does that mean i need to use only the DVD-RW 4X discs?

I have been trying to use the Memorex DVD-RW 2X disc 4.7 gb and they don't work.

Is this my problem.

My Drive is a Pioneer DVD-RW / DVR-105 ext. Firewire drive.

um you should be able to use a lower speed disk, have you checked with the specs to see what the max speed for dvd-rw is on your drive? :/

sorry, just checked your drives specs and it's 2x on dvd-rw.
well what software are you burning with?