Version: 2.0.96 (using KDE 4.2.85) Installed from: Ubuntu Packages I've renamed two files within my collection (using "mv" in konsole). After doing this, those tracks disappeared from the Collection. Then, I've rescanned the whole collection (using Configure/Collection/Rescan Collection) and this made those tracks appear again in the collection. BUT, the other 13 tracks (which I had not renamed) disappeared..!
*** This bug has been marked as a duplicate of bug 186169 ***