I have the same thing. I tried everything. When i click on ‘show topic’ on my ne forum, or any other – i am redirected to main wordpress page.
The most stupid thing is that just after i installed bbpress, it was working. But after i was trying to integrate with wordpress – several bugs have occured, so i deleted bb and cleared the databe, but now after another install, it simply doesnt work, just like the topic says.