After several tries I can't get the link to on of my videos on youtube to work.
The link:

http://www.youtube.com/watch?v=almzR3uHR2M&list=UUNDupj5F5COp9xcLXE3zZgw

but somehow the link doesn't work. What's the problem?

Raphael,

Our script extracts the YouTube video ID out of the URL, but wasn't doing a good job when the URL contains more than just the video ID.  In your case, the Video ID is "almzR3uHR2M" but our script grabbed "almzR3uHR2M&list=UUNDupj5F5COp9xcLXE3zZgw", which includes the separate "list" argument.  I've fixed your video and adjusted the pattern in our script so that in the future, it will correctly identify the video ID even when the URL contains additional parameters.