I don't know if my problem is related to this (moderators, feel free to create a new thread). But I recently changed a lot of passwords. I find that at least one item in my Logins on the iPhone has the old version of the password (and username and memorable info). I made the change a while ago,, and Dropbox shows the keychain as recent, so it cannot be a matter of Dropbox not having xompleted its sync.
Using 1PW 3.8.9 on Snow Leopard.