Well I am having the same problem with mine. Except I am using a different bbcode than the one that comes on the forum editor.
Is there away to fix this in the raw code? Maybe some way of truncating the link to the next line, or allowing more characters to be used so long as the right bbcode tag is used? Problem is, that I would like to have those long urls but only with the right bbcode tag used, or even with the html tag ie <a href=" http"//mydomain.com/multi-lineurlhere">Click Here</a>... At this point the forum does not allow for html tags to be used at all.