cdrecord writes nonportable DVDs

Cdrecord is giving me a problem: the DVDs it writes are readable only on the machine where they were written. It wasn't always this way; older ones from the same drive/machine/software are readable anywhere. I suspect that the drive has somehow gotten out of calibration, but I'd like to avoid replacing it. One indicator is that cdrecord gives me the message: cdrecord: WARNING: Drive returns wrong startsec (0) using -150 I googled the message and got many results, but none seem particular to this message. I don't even know if the message is relevant to the problem, or if there's anything I can do to make it go away. Is there some way to write the DVDs more conservatively that's likely to cure the problem? Paul