Outlook 2013 Reminder-Popup

[KRuprecht]

Since migrating from 2010 to 2013 there is at least one disadvantage: Outlook reminders are shown even for tasks that are ready! (they have a remider date set in the past, but are ready!).
And, they all come form my hotmail-account (the tasks from office 365 are ok).

Any ideas to solve this?

Thanks a lot!