This might not be considered as bug, but rather a strange behaviour. At least thats my opinion.
I posted a link recently this way:
[url=http://www.dn.se/DNet/jsp/polopoly.jsp?d=1298&a=511671&previousRenderType=6]KRÖNIKA: Rika bilförare är de verkliga vinnarna (www.dn.se)[/url]
And it becomes this way:
KRÖNIKA: Rika bilförare är de verkliga vinnarna ([url=http://www.dn.se]www.dn.se)[/url]
Notice that the short URL becomes an own url in the title of the long one. Two in one that is.
My opinion is that any text between the url tags (if it's written to be title like above) should be just that; a title. It should not be able to be parsed as an url itself.
Well, the world may have bigger problems than this, but I thought it could be worth mentioning anyway.