As a heads up to everyone, you might want to use a unique password for this site, as opposed to one that you use all over the place. It appears that YaBB is vulnerable to a cross-site scripting vulnerability. This is the same type of vulnerability that lots of other software packages were found vulnerable to. However, most of these other packages got fixed. This issue has been known since early January, 2002. For more info go check here:
http://online.securityfocus.com/cgi-bin/vulns-item.pl?section=info&id=3828. The long and short of it is that someone could post a message to the board and everyone who views that message will have the cookie containing their login information stolen. Nice, eh?
-Steve