I just installed the RC version, but now I can't log in.

Well, I can, but something seems to be hung up.

When I enter my username and password, I'm being told that I'm being logged in (the please wait screen). Once that screen goes away, I'm no longer logged in. I'm using the correct username and password, so I have no idea what's going on.

Sounds like a familiar problem...

Did you try clearing all cookies and cache n temp files?

Yup...still can't.

I am not going to upgrade if it means every one of my members is going to have to clear their cookies before things will work correctly.

Yup...still can't.

Make sure your cookie settings are correct in the admin area! :3

Now that I'm at home and on a different computer, I was able to get in.