I've been using the latest CDBurner XP version with no problems for a month or so now but only writing MP3 files. I tried writing some WMA files created prior to Windows Media Player 9.0 I think. In the file scan mode after clicking 'BURN', it progresses quite fast and then writes the disc quickly. When played, all the tracks are empty. I then wrote the same files using the NERO burner software (Ugh!) which came with my Sony DVD unit, and it created the CD's just fine. Your website's format chart indicates that WMA is supported. Any tips?