Harold, if your site depends on incoming search engine traffic I'd recommend you take a look at my "webmaster mistakes" thread on my site before following through with using a subdomain for your forums:
http://www.undergroundnews.com/forum/ubbthreads.php/ubb/showflat/Number/18796/page/1#Post18797

I am a Web Development Contractor, I do not work for UBBCentral. I have provided free User to User Support since the beginning of these support forums.
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