At first I thought it might be the system, but in fact I see exactly the same results on a W510 and W520.
I was seeing it with an older Sony DVD writer and thought it might be the laser, tossed it and bought a new LG unit and the same problem (on two different systems).
The common thing is that both are running on USB2.0 mode on the NEC (Renesas) USB3.0 ports. It occurred to me last night to try to find a USB port that is on the Intel USB subsystem.
It's really insidious. It's not just on USB but also on the drive bay drives. It's happening with both the W510 and W520. So far I've been using Memorex DVD+R DL 8x. But even the internal drive makes coasters 30% of the time.
Software doesn't seem to make much of a difference. The new Corel software doesn't offer a compare operation, and the Sonic stuff runs on both and has compare but still gets errors.
Right now I'm suspecting that it might really be the Memorex media. I had similar problems though with TDK in the past. But I never had any problems buring on any of the hardware with my T60p and Windows XP. Even the T60 won't burn USB but the common thing on all is WIndows 7. Are there any Thinkpad / Win7 secret settings that might be wrong?
But the other side of the media equation is that Sunday I went to every local store looking for DVD+RDL media and the only kind I could find anywhere was Memorex. If Memorex media had problems everywhere it wouldn't be the dominant store choice. So it comes back to the system again.
By the way, the Wndows ISO burner doesn't finalize the disc. On Dual Layer discs this leaves a portion of the disc only half written, and I can pretty reliably get errors at what I think is the transition.