[_ck_]

No, if you have bbpress and wordpress integrated, and you are with bbPress 0.9, you should stick with WordPress 2.5 because that’s the only version that works with bbPress 0.9

There is nothing wrong with WP 2.5 and no need to upgrade to 2.6, because if you do, you’ll need bbPress 1.0 alpha which is unstable and has bugs.