Files don't display on Vista desktop

In Vista, sometimes files can be selected via "Desktop" in Windows
Explorer, and/or via C:\Users\[username]\Desktop but the files cannot
actually be seen nor selected via the desktop itself.

Sometimes I hit the F5 key and they appear, sometimest they don't.
Never had this problem in XP.

I view properties for the files and Hidden is not checked. I have
Show hidden files and folders and Show protected operating system
files and folders enabled.

Today's maddening example is that I created a shortcut to Programs
and Features by the usual right-click, drag, select Create shortcut
here method, but nothing appeared on the desktop. I opened Windows
Explorer and sure enough, the files are there.

They aren't under my task bar, and I moved all icons to the center of
the desktop, use the keyboard shortcut to select all files, and moved
the icons around to see if any would get dragged onto the viewable
portion of the desktop in the process (meaning they were on the
desktop, but off-screen).

A solution for getting files to appear on the desktop would be greatly
appreciated.