This new version of vbulletin has a new feature that will help insert videos in your posts.

When you are creating your post you need to look at the icons just above the box you are typing your text into. In the lower row you will see the font icons, the alignment icons and the insert icons...

Click on the one to the far right (looks like a film strip, 15th one from the left in the lower row or 5th from the right) and then past your video link into the pop-up window. Your video should now apear when you post your commnets.