My forum url is set correctly so its not that

I know locally i edited your plugin and removed that bburl code in it and it worked well after that.
As regards bbcode, i actually meant a tag. Could you not get the plugin to look at the body of the text and if a tag exists break there instead of the default in the admincp option of your plugin ? Would seem the likely solution.
So check if $tag exists else $mydefaultbreaksetting ?