Your web-browser caches HTTP flash videos from YouTube. Make sure to clear the cache of your web-browser before downloading HTTP videos that you have already watched with Replay Media Catcher.

Please also try the latest version of Replay Media Catcher. It has a tool for saving YouTube videos from the browser cache. The tool is called "Video History Tool" (in the menu select Tools -> Video History Tool).

Please note that some streams from YouTube use secure RTMPE protocol. Downloading/capturing encrypted videos is prohibited by DMCA, so RMC can not download/capture such videos. But you can always record secure videos from your screen using screen video capture software like Replay Video Capture.

If RMC is not working for you, please post a link to the video that you want to download and we will suggest you the best way to download/record/capture the stream. You can also ask your question in the Applian User Forum.