Al seems fine to me with the forum.
From the chatter out there, this redirect could potentially be originating from one of the Google Ads running on site, running some script.
Weird that they would be able to sneak it in - Google usually kills that kind of crap.
Please do let us know ASAP if anyone else notices any weir stuff.
Try to pay attention and to see if you can see the correlation with a banner add displayed on BWE at a time - we'll disallow it.
Internet, crazy place