The regular expression should be:
Code:
http://youtu\.be/([\w-]+)\??[hd=1]*[&t=]*([\d]*)[\w]*
It was missing the - after the \w in the first parameter.
\w = any latter or number or underscore (but it doesn't match the dash (-) so you have to add the dash manuall because youtube ID's can have dashes in them.
I'm not sure if those double ?'s are right but if it works with other videos but not all I'm sure the dash is the problem.