I will check WordPress.org and file a bug there or see if anyone else has had a similar experience. It just seemed somehow related to this weirdness.

Neither editing my own or anyone else's profile causes a problem. No matter who I am logged in as.

It has to be something local to your setup.

That means that I can only think of three scenarios:

1. The problem is a general problem with 1.0-alpha
2. It has something to do with my DB and it's implementation with WP/bbP
3. A problem with bb-config.php? (though unlikely given the nature of the issue)

I also deleted the entire modified template folder and replaced it with the original Kakumei template for testing reasons but the problem persisted.

You can just switch to it temporarily, then test and switch back.

I just deactivated all my plugins and had another try with the testuser account but it will still change the PW if I do a Profile change (User or Admin induced).

Best
Lars

I joined and logged in to your site. I edited my profile and indeed the password stopped working. First things first, try deactivating the signatures plugin you are using and see if the problem still occurs. If not that's the culprit and it needs to be modified by the plugin author to stop this behaviour.

I assume that would be the shared key under wp_users in the DB (user_pass).

First I noted the hash for my regular testuser account (1). Then I made a profile change for that with the admin and wrote down the new (now changed) pw hash (2). Then I made another change with the admin to testuser and, again, I get a different pw hash (3).
However, when I aquire a new PW with testuser and change that to the original pw for testuser (4) from step 1 so that pw (1) and (4) match, the hash is again different even though it's the same pw.

Then I made a second testuser account and compared the hash after an admin profile change (5) with the hash from (2) and they differ.

Hope that makes any sense.

See, I have this testuser account with it's own PW. Now when I logon to
Admin-->Admin Panel-->Users-->Edit testuser
and change, say, the Custom Title with the PW blank, confirm with 'Update Profile' , logout of Admin and try to logon to testuser again, the old PW is no longer valid.

Now when a user's Profile data is changed on the Profile Tab (either by the user himself or any Admin/Keymaster), this users PW receives a reset leaving him unable to login with his old PW and he'll need to request a new one.
A temporary solution seems to be to let users confirm their old PW on the Profile page everytime even if they only want to change other data like their name.
However, this is of course only a workaround for the user himself because the Admins/Keymasters don't know the user's PW.
For now I settled on changing privileges etc. directly via the DB which will leave the PW intact, still it's quite a bit of extra work.

Is this a known issue with the Alpha release?

Thanks a lot
Lars