won't log me in

Is this when you check the username/password when creating a new twitter feed? I've heard of any issue (probably some encoding issue I ought to fix) when passwords contained unusual characters. However, this _only_ affects the checking of the password, not the "real" posting to twitter - if you're sure your password is correct, ignore this warning for now, the posting will actually work.
Once you've set this up, check back under "my twitterfeeds" a few hours later to see if posting succeeded - if there really is a problem with the password, it will say so when you hover over the status icon to the left of the feed listed.