Problem with password change...

I have a new Zoho CRM account. I am trying to change my password, but the Setup->>Change Password function is telling me that the old password I am entering is incorrect. I have tried several times and have entered the old password very carefully, so I don't think I am mistyping it. Additionally, I had just logged in successfully with the old password. Is there some minimum period of time that must pass before I can reset the password? Any help would be appreciated.

Thank you.
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