User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 See the steps to reproduce below. You should be able to reproduce with 100% success. Reproducible: Always Steps to Reproduce: 1. Go to any video on Youtube.com 2. Navigate away from the video by clicking on a link. 3. Click the "Back" button to return to the video. 4. The video and apparently the entire player will fail to reload. Actual Results: Youtube video player would not load. Expected Results: Youtube video player should load properly and begin playing the video on the page you navigated backwards to.