Collapse all groups gives erroneous "There are no items to show"

I have a task view that is grouped by category. With all groups
expanded, selecting View/"Expand/Collapse Groups"/Collapse All
Groups, I get no tasks showing and an erroneous message "There are no
items to show in this view."

Any ideas on how to correct this?

I have a work around by which I can get the collapsed category groups
to show by clicking on a different group in the navigation pane then
clicking again in the navigation pane on the original task view.

Specifics of my task view: sort by due date, filter by complete = no

I am using Outlook 2007 SP2 on Vista Home Premiun SP2

Thanks in advance for any help you can offer,
Jim