Applications do not appear on taskbar after SP2 update :-(((

Hello all,
i realy hope someone can help me out here:
after installing Windows XP SP2 and booting the system,
no applications appear in the taskbar to switch between.
ALT+TAB still works and shows the apps available, but the small windows in
the taskbar are not available. I have tried to change every setting available
in the taskbar options and folders and have come up short of a solution.
my hunch is that i can add a "special" folder (like the minimize windows
button) which will show the apps again.
please help me out here,

thanks a lot!!
--
Haim.