If you enclose a URL with [font], [size] or [color], the URL isn't parsed and just displayed as regular text.

[B], [I] and [U] don't effect it though

Some examples:

http://www.hexus.net - Font
http://www.hexus.net - Size
http://www.hexus.net - Color
http://www.hexus.net - B
http://www.hexus.net - I
http://www.hexus.net - U
- Indent

Not expecting a fix, just documenting it really