I just got myself a DVD-burner (Pioneer DVR-108) and the first disc I burned to check compatibility with my Denon DVD-2900, was a DVD+RW (the *least* compatible format with standalone players). Surprisingly it had no problems reading it, even all the way to the end of the disc. I also have a DVD-R that it reads without problems (burned by a friend). I think the issues reported here with the DVD-2200/2900 and burned DVDs, might be related to the fact that a lot combinations of burners and media out there can result in discs that are not exactly coasters, but still have a very high error count.
Anyway, to make it easier for people to use burned DVDs on DVD-2200/2900 here's a list of the media, burner and software I've used with success:
Pioneer DVR-108 with Verbatim 4x DVD+RW dye: MKM A02. Software: Nero Burning ROM Ultra Edition 6.3.1.15
NEC2500 with Bulkpaq 4X orange top general purpose media. Dye: Princo. Software: Unknown.
I'll be receiving more media next week so I'll update the thread then.