MYSQL Backup addon error

[pfabrick]

We've used this tool on multiple Zen Carts in the past and now one of them has started throwing an error when running the tool:

Result code: 2
0 => mysqldump: Got error: 1045: Access denied for user 'username'@'localhost' (using password: YES) when trying to connect
Failure: The database has NOT been saved.

Where username is our user name for the database. It seems rather odd that we're logged into the admin and then the mod is unable to use the same user info to run the backup. We're using ver 1.3.5 on this store.

Thanks for your help.