I've noticed that the quality of my reading from and writing to recordable DVD media decreases with increased temperature.
For example, I have a Toshiba SD-R5002 DVD recorder and some 2x Princo DVD-R media. I have the side of my computer case off. When the room temperature is about 26-27°C, the recorder sometimes switches to 1x from 2x when recording on the aforementioned discs. At a temperature of 20°C, it records at 2x throughout the whole disc.
In my Lite-On (JLMS) 16x DVD-ROM drive (166S), a Princo disc can only be read for about 1 minute after insertion into the drive, after which the drive gets "lost" and spits out the disc, or assumes the disc is no longer in there. This occurs when it's warm in my room, 26-27°C. When it's cooler (20-21°C), a disc can be read for much longer than that.
Do DVD-R discs really expand that much over a few degrees to be out of the tolerance ranges of the drives? Or is it something else?