Thanks Xaver. I owe you an apology. My problem was due to my lack of observation of detail. What was actually occurring, was that the size of the file I was trying to add in Track 8, a WAV (just for trial purposes), was showing up as 0:00 when I imported it into the Music window - and I hadn't noticed that! I feel somewhat abashed. I can't say what caused the problem; the file size showed correctly in the folder where I had it stored. Anyway the fault didn't appear after I opened the file in my audio editor and re-saved it, so all's well now. I haven't experienced any error messages but it sounds as if you may have experienced a little computer glitch. Thanks again for your effort to help me. Regards,Don.