Possible bug: every workday starting 10 june 2013
When I enter "every workday starting 10 june 2013" (a date in the past), the system does not behave as I expect. The first task is indeed created for June 10, but the next task is not for June 11, but for June 17.
Every recurring task that is overdue, when completed or postponed, will move to the next occurrence according to its formula.
That said, 17 June is the correct date as when you complete this task today, this will be the next upcoming workday. It's not possible to continue completing recurring overdue tasks and having them rescheduled to another overdue dates. This way you don't have to click on it multiple times before you get to the next occurrence.