I also got problem with integrate with wpmu 1.5, the user sharing is ok, but it got some login cookie problem, when I logged in wpmu, I need login again in bbpress.
I’ll have to download the final release and check integration.
In addition, I found the problem only happens when you install bbpress in a subdomain of wpmu 1.5.1 site, I changed to install in a subfolder, the cookie problem is gone.
That’s interesting… glad you got it sorted. I’m still having problems despite being in a sub-folder… I’ve tried countless variations in my config files, but I’m still in cookie hell.
WPMU 1.5.1 install is (www.mainsite.com)
BB Press 0.9.2 is (www.mainsite.com/forum/)
This is what you meant by sub-folder isn’t it?
I’ve just left it for the time being in the hopes that someone will post that they had the same problem but that they’ve solved it. Lazy, I know, but I ended up dreaming of config files the other night. I’m actually feeling pretty numb about the whole thing now… I’ve managed to integrate before with previous versions of MU and BB, but I just can’t fathom this one. Your post (and the absence of others with problems) leads me to believe that this is a problem of my own making.
You’re not alone!
I just upgraded my site to mu1.5.1 and bbpress to the latest release and now cookies wont work. I’ve tried everything, all the ways listed here and on other sites and no luck.
Its probably because wp2.5 changed cookie styles so the old way doesnt work anymore. I know because I tried my old config and it didnt do anything.
WPMU is adding some extra information to the end of wordpress’ username cookie content.
For example, the old cookie content is simply “admin,” while the new cookie is “admin” + a number like “%7C1211540101%7Cb954a41e23200ea6951bdeb405dc5237.”
Perhaps this is some kind of hash? I know WPMU 1.5.1 added a salt key to the wp-config.php file, so maybe that has something to do with it.
WPMU 1.5.1 is probably only compatible with bbPress 0.9.0.2
I managed to fix this in the end… italways’ post got me thinking, as he mentioned problems on sub-domains. Despite my BB press directory not being in a sub-domain, looking at the MU forum, a lot of people seemed to be having problems with the 1.5.1 install switching sub-domains with sub-directories. Looking at the forums here again, there was a topic about integrating BB Press with MU on a sub-domain which included adding the following code to bb-config:
require_once('/home/mydomain/public_html/wp-blog-header.php');
This is the relative path from the server root. Adding this seemed to fix the cookie problem and BB Press 0.9.0.2 is now successfully sharing cookies with MU 1.5.1 for me. This is the only change from the standard integration settings. I was trying all sorts before trying that, with absolutely no joy. Quite why this worked, I don’t know… hope it works for you too.
There’s a bit missing from the end of that code… should read:
wp-blog-header.php');
The end of the line anyway…
Didn’t work for me, it started to redirect my forum to the signup page.
Must’ve missed your post 
Tried that and it worked, all I was missing was the salt line.
