This problem occurs when the file browser takes a long time to refresh.
Forexample, it happens when another Windows application is dragged over
the applet while a drive (which is mapped over the network and contains
many subdirectories) is opened.

Please use the attached test case and the following steps to reproduce the
problem:

Steps:

a) Mapped a *slow* network drive with around 70 folders.

b) Load up the applet on Windows 2000/IE/Netscape

c) In the "Specify Source Directory" screen of the application, press
  "Browse" button and key in the network mapped drive name in the
  "Choose a directory" screen and then hit enter/return key.

d) Have a new browser window with some images come into foreground and
   minimize it immediately. The applet area will have this image stuck for a
   "few seconds" after which it gets repainted.