**** UPDATE – This issue is resolved in the Project Server 2010 October 2011 CU ****
You will see this when the user has created a new project plan and assigned generic resources. As generic resource can’t own assignments the user who created the Project Plan will be the assignment owner as shown below:
When I log into PWA, the reminders web part will show 2 new tasks assigned to me as seen below:
Clicking the ‘2 new tasks’ will load the tasks page, but here no tasks are displayed as seen below, worth noting is that this is new PWA instance so I don’t have any actual assignments!
The reason why you see this is because the SQL query used for the reminders web part selects a count of all assignment UIDs where you are the assignment owner and the assignment is new where as the query used for the Tasks page filters out the generic resource assignments. In Project Server 2007 the My Tasks page used to included the generic assignments but a lot of people didn’t like this so I guess this is why Microsoft changed the behaviour.
One option to save confusion is to remove the new tasks feature from the reminders web part. To do this edit the reminders web parts, expand out the Project Web App menu and uncheck the ‘Show new tasks assigned to me’ option as below:
Click Apply then stop editing the page and you will see that the new tasks section has been removed. Please note, this change will affect all users. If you repeat this change but select the ‘Personalise this Page’ option from the welcome menu as below then make edit the web part to remove the ‘Show new tasks assigned to me’ option this will only apply to the current user.