The username I used is [email protected] and I'm using the reset link on the login page: http://mining.bitcoin.cz/accounts/password/reset/
I tested password reset now and it works fine. I'm receiving many similar emails about password reset and every time people find that they made some mistake . Please be sure that you really typed same passwords on both forms (reset & login) . Also try to delete passwords from browser's password manager; many people told me that some browsers are using old password for login form.
Ah, I see. Chrome decided my email address was my username. Got it sorted, thanks!