To help out others with the same problem who stumble upon this thread, as I did:
you should recreate the file that you removed or renamed (just take any other qlikview file, copy and rename (case sensitive)). This document now reappears in you user's documents tab, together with the reload options you had attached to the file before deleting.renaming it. You can now set the reload option to "none", and the task in you status tab will disappear. Now you can delete that qlikview document again.