Losing Focus

I have a MDI app with a TreeView set to alLeft of the main form and a
toolbar with a combobox set to alTop - MDIchild forms take up the main
form client area - I've found a very strange behavior regarding focus
- if one of my MDI child forms has a ListView component on it and it
has the focus (the dotted rectangle line around it), when I mouse
click on the TreeView or the tollbar combobox, the dotted rectangle on
the ListView on the MDIchild form does NOT go away - this is causing
problems because when I click back to the MDIchild ListView, the up
and down keys no longer work to move the lightbar up and down the
ListView component - my other components on the other MDIchild forms
do not display this behavior - when I click on a non-MDIchild
component, how do I get the ListView to loose the dotted lines
(focus)???

Thank you...

Ralph Freshour