I tried to post this in the comments off the plugin homepage, but Extend won't recognize my login. Weird.
Anyway - if you are running 0.9 and plugin browser, you probably see no version listed for all plugins in the 'Local' column. This is due to a change in how bbpress stores the plugin paths in the DB (_ck_ clued me into that) The fix is easy. In the main plugins-browser.php file, add 'user#' before pb-- or pb\-\- on lines 681 (in the preg_replace statement) and line 698 ($plugin['version_local']) Once I did that, the browser worked fine with correct version info, showed updates that existed, and installed them no problem.
I'm sure the Wordpress plugin update stuff will make it into bbpress soon, negating the need for this plugin (to a point - the browse part is still great) but until then - this will get you going.