I have (or did have) this working nicely on a few sites with different groups posting videos to their channel and then being published on the sites. In the last few weeks I've notice that the videos showing up were reducing. The videos concerned are still sitting there in the YouTube accounts but they no longer show up in the WP site. I re-upped a video and it appeared again but I can't keep doing this.
Did something change recently on YouTube. When checking my feeds I noticed it's harder now to identify what the username of a YouTube account (not a Tubepress problem I know)