The discs I've burned on this unit look great and play fine on the DMR, but my APEX 600A won't touch them, and my Pioneer DV-505 plays them for a while and then freezes in various places. I am using Digital Media general purpose blanks (one-sided, 4.7 GB) which cost me $4.99 each at Circuit City. I don't want to keep throwing away five bucks a shot for discs I can't bring to a friend's house and play. Anyone else having these concerns? I've ordered 25 4.7's from Apple.com, which I hope will work better.