Does anyone know if there is some setting in DVD Studio Pro that determines whether DVDSP will burn to a DVD-R disc or DVD+R?
I burned a DVD-R and it will not play on a DVD-R only player, but it will play on other players, I am so confused...

This seems unusual. Their is no setting in DVDSP for dvd-r vs. dvd+r discs; as long as your burner supports it, it should work. Does the disc play back in the computer you authored it with, or only in other players? A little more info and we can probably track down the issue.

The disc image plays back on my G5 but once I burn it through the Finder it won't play back I get "supported disc not available". It also only plays back on DVD players that support DVD+R. If I try to burn straight from DVDSP I get error messages and bad burns.

Are you burning a disc image (.dmg or .img) or are you simply burning the VIDEO_TS folder? Try building the project in DVDSP and burn the VIDEO_TS folder. If you have Toast, create a new data disc, click on new disc, add the VIDEO_TS folder, and create a new empty folder called AUDIO_TS .Make sure you have it set to DVD-ROM (UDF) and then burn. Try lowering the burn speed as well. It could be that you may have a bad batch of discs. A lower setting for the burn speed (such as 1x) may rectify this.

That did it! Thanks

Glad to hear it! It seems unusual that Build/Format doesn't work in DVDSP. If you post the error mesages it throws up, we may be able to figure that problem out. Otherwise, just keep burning the VIDEO_TS folder . . .