I tried this again with two more substantial PCs, both Windows 7 machines. One, a recent build, responded with the same error message when attempting to burn WMA files. The other, also recent, started as though it would succeed, with “Writing lead-in area”, whereupon the status of each individual burn track, 40 minutes of music, changed from “In Queue” to “Complete”, and the process jumped to “Writing lead-out area”, taking perhaps 20 seconds, both in Test and Burn modes. In “Burn”, a small 2 KB unplayable track was written to the blank.
All tracks play normally using Media Center. Log files have been sent to johnt.