No problems here using toast 10.0.2 and Lion 10.7.3.
I use imation -R discs, the non-printable kind. I label them with a sharpie. Coasters are extremely rare. Perhaps try imation and see how that works. Also, maybe it's your dvd players. The older players have more trouble reading the discs. I never had any luck with verbatim discs. I've used sony DL discs on occasion (successfully).
SONY DVD player is brand spankin new.
Have not tried Imation disks.
Its just puzzling that Leopard and Toast 8 produces a DVD where as Lion and Toast 8 produces a coaster.
I tried not printiable Verbatims. Same result.
Need printables for the projects that I do.
Appreciate the suggetsions.
Will be methodically dilligent and post any results here.
any help from any others would be appreciated.