Kind of. My Leopard disk is not an original, I made a backup of a friend's install disk (naughty me but, hey, free software - meh) years ago and burned it to a DVD+R DL disc for my PowerBook G4 (which at the time only had Tiger on it). That worked nicely. Then in 2009 when I obtained a MDD (June 2003) I found it didn't read the disc, spits it out. Back then I didn't think too much of it and just assumed the drive had a dirty lens, but I forgot about it until the other day, and when it spat the disc out again I again thought at first this was because the drive was a bit iffy (even after I ran a lens cleaner through it), hence me creating this topic. It didn't occur to me initially that the drive probably will work with an original pressed DVD9 disc so this topic is kind of moot really. I think given the drive was made in 2003 and DVD+R DL media didn't begin to become widely supported until mid 2004 (according to Wikipedia) that may be why the drive doesn't like it - it just doesn't support that kind of media. So yea it's the fact it's DVD+R DL that's the problem, and I don't actually need a two disc version of Leopard on single layer discs at all, I just need an original DVD9 version of it.
I have however solved my issue now though. Back when I did it before after getting the MDD I used Target Disk Mode, as MysticCow suggested I do now, which I have tried but for some reason now it won't work. The installer loaded and ended up hanging. No idea why, but my MDD's been a bit shady recently (I think the PSU's on the way out... Again). Anyway that's basically it, I tried TDM, didn't work, so I went looking for a single layer media version of Leopard, which doesn't exist. It wasn't actually until after I posted this I started investigating the various topics that were coming up about actually making your own single layer disc by, using sparse disk images and stripping out components like xcode tools, language packs and printer drivers.
I thought I was onto a winner with that one, followed a guide I found on insaneleymac, burned the disc, and wouldn't you know it the damn thing didn't work. Well, it booted but got stuck seemingly forever on that initial grey loading screen with the Apple logo and the spinning wheel icon. When I looked through the topics on making these discs I found a lot of people had the same issues back then and no one seemed to be able to offer a solution. In the end I solved my problem by using of all things a USB stick. I didn't know you could boot from USB sticks on these old PowerMac's but it turns out you can, provided they're formatted properly with an Apple Partition Map and you plug them into a direct port on the Mac and not a hub like on Apple Pro keyboards. So, yea, solved. It took three hours to configure and install but I assume that's mostly down to it being USB 1.1.