DVD copying

Right - this is strictly Kosher, I'm not asking how to pirate copyrighted material here...

I've created a DVD (martial arts stuff, a seminar with a 10th degree) using iDVD and the master copy works great. People in my club want copies, but the G4 I use for editting is in another building and walking down there and watching a progress bar for 1/2 hour isn't fun. So, I want to use my G4 here to copy the discs.

Now, I've opened up Disc Copy (OS 10.2.5) and made a disc image of the master using the "DVD" option. I've then burned this to a disc, but it doesn't want to open in anything other than the Mac. My PC won't even recognise it, nor does a home player. The G4 sees the disc, but won't play it unless I point the player to the Video folder - this leads me to believe it's been burned as a DVD data disc rather than a video disc.

Is there anyway I can copy my DVD on my G4? Or do I have to burn it fresh from iDVD every blummin time. :(