It's like that in all browsers afaik. It's where a user types a continuously long string e.g.
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
and as urls are bigger than the box, it also occurs with them.
This will appear out of the allotted space, if it was aaaa aaaaa aaaa however it would be fine.
We know about the bug and it's on our todo list

Thanks for informing us about it though

One solution you as a user could use for url's is to post them in bbcode e.g.:
CODE
Look at [url=http://skladiste.wen.ru/m9/embeded.jpg]this[/url] picture
Which would output:
Look at
this picture
Edit: That example isn't good in this situation, but you get the idea for any other user that wants t post a long url