Thanks to John I've tried the Pio media. Can't say if it's really from Pioneer even though the graphics are similar but I bought a hundred. So far (I've burned about 25 discs) so good, no coasters. I tried it at 4X just to see how it went and the discs came out so hot it worried me. No sweat because I only burn at 1X for the real world. But the discs which were filled up played right to the end. I've had problems before burning at high speed near the edge of the disc due to disc wobble at the edge.