Anyone else have this problem?

Sometimes when I boot up into XP, the icons for programs that launch into the system tray at startup dont show up. The applications are still running (i can see them in the process list in task manager), but the icon is never added to the system tray. Volume Control is an example of one of the many (random) icons that may not appear (It doesn't always happen).

And no I don't have the "hide icons that aren't used often" option enabled.

Thanks in advance.
-Kory