This is probably Direct Unpack continuing its job after the download was finished. UnpackPauseQueue is for post-processing whereas direct unpack is by definition performed parallel to downloading. You can disable it via option DirectUnpack.
This log doesn't contain info about error message for articles. These messages are logged as DETAIL. Please activate option DetailTarget and check the messages tab.
Most likely cause - the files are now longer on your news-server (error message "Article not found").