This white box is the result of putting the entire url between the youtube tags. [YOUTUBE] [/YOUTUBE]
You don't put the whole IRL in between the [ youtube ] marks. Just the code number. So, if the IRL is: "http://www.youtube.com/watch?v=r5Bv6XS1V3A" Just put the "r5Bv6XS1V3A" part in between the marks (without the quotes). r5Bv6XS1V3A For yours, it would be [ youtube ]76vgtDxnilE[ /youtube ] and you would get: 76vgtDxnilE
I know AB, but a lot of people will do it with the whole link. On some sites if you do that the youtube link will cause a redirect to youtube instead of just showing the video. I was testing what would happen if I put the whole link. On this site it just gives you a white box.