While trying to clean up some files, I opened the My Music folder and found a subfolder of files that were copied from lps by a software that MS put out some years ago. Originally, each track was saved as a .wma file...but now, for some reason, all the files have an extra extension of .ptl. So now each track will read like amazinggrace.wma.ptl and I can't do a thing with them. How did this happen and how can I fix it so I can burn them to a cd?