I've seen others with this issue, but never with a real solution. I've installed BuddyPress successfully via the wizard as well as a site-wide forums setup. But when I went to http://mysite/forums it keeps reverting back to the home page.
So I went to Settings > Forums to check out the bbPress settings and saw that under Archive Slugs, the Forums Base was set to Forums and had a conflict message beside it saying it conflicted with BuddyPress' Forums page.
So I tried creating a new page called Discussions and in the BuddyPress > Pages area set the Discussion Forums page to my new Discussions page. Then when visiting http://mysite/discussions I see a static empty page.
So far the only way I can get this to work somewhat is to place the bbPress shortcode
[bbp-forum-index]on the Discussions page to get the forum to show up. I would prefer to have it simply work the way it was originally intended though.