Just a quick check i am sure you have done this but have you tried to create your own view on the task list to see what it returns. This will tell you if the views are corrupted or something deeper.
Try creating a new view and in the filter by section choose "assigned to" and in the filter section put [me]
this will create a list which should show you your tasks.
If this works the error is not on the list but something specific to the views.
Andy Reeves
