I have a Matshita BD-MLT UJ267AM drive (blu-ray writer). It cannot read dual-layer DVDs (it tries very hard and then only says no disc in drive). It has no trouble with single-layer DVDs. These are all factory-pressed discs, mainly movies. It's also not at all random. Single-layer always works and dual-layer never works. The dual-layer discs of course work fine in other drives.
I suppose this is a hardware failure, but does anyone know of anything else that might be causing this?