This only happens if the two password fields contain different information. I have done several restorations myself using this version of Akeeba Backup without bumping into this kind of issue.
I suspect that either your browser is accidentally filling in a different password or something on the server side is somehow corrupting the password you are entering (it happens on some servers if the password contains anything other than ASCII letters, numbers, dashes and underscores).
One solution is to not fill in a password at all. You actually don't need to fill in that field; it will just keep the existing one Joomla knew about at backup time. That field is meant for overriding passwords, e.g. when restoring a client's site for debugging or development purposes which is common among extension support folks like us and site integrators.
Nicholas K. Dionysopoulos
Lead Developer and Director
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