strange happenings on desktop!!!

I recently purchased new PC with Vista.
While surfing or working on or with some programs
when I go to start and click on my documents or
my computer, the pop-up box appears, but I cannot see
anything in it. If I move cursor around slowly, it will show
the icon identification, but I cannot see the icon.
If I shutdown or log off and log on again, everything goes
back to normal. Please advise.
Thanks in advance.

KT