systray malfunctioning

[Grant]

My wife and I have identical Dell Vostro 1320 laptops and I've always
tried to keep their configs the same.  The xfce4 systray on mine works
perfectly, but my wife's has always malfunctioned and I've never been
able to figure out why.  xfce4 panel plugins work perfectly, but other
applications such as orage, blueman, wicd, and twinkle which should
appear in the systray do not.  The systray icon for twinkle actually
shows up in the center of the screen, but the icons for the rest do
not show up at all.  I'm not sure where to start with this, does
anyone have any ideas?

- Grant