Did you set a Password within Acronis to make the clone? If so, it is different than your Windows password - always best not to set a password when using Acronis. I never use a password in Acronis.
You can edit the scheduled task ("Edit the selected task" button on the Active Task panel) and set the correct password, or perhaps remove the password altogether. You can find more information on how to edit scheduled tasks in Chapter 8.2 "Managing scheduled tasks" in the Acronis True Image 9.1 Enterprise Server User's Guide (click here).
Bear in mind this is just a guess, I could be wrong.