alt-tab switching when running wine does not work

[john-thomas richards]

when running any application via wine, i am unable to alt-tab switch to
another application.  technically, focus does change but alt-tab does
not bring the application to the front.  i am running xfce4 rc3 in
debian testing, compiled from source.  what could be the problem?
-- 
john-thomas
------
There are two kinds of fool. One says, "This is old, and therefore
good."  And one says, "This is new, and therefore better."
John Brunner, science fiction writer (1934-1995)