RIght.....worst feature: When you close Opera down, it closes all the workgroups. They are still there but all the tabs that have been assigned a workgroup have been removed. So you have to move all the tabs backto their respective workgroups.
Otherwise, you do have to use the password, and if you put the wrong password, it just sits there and looks blank at you. So it works.
But this failure to reload the workgroups is a pain. Please fix this bug.