The following are how I repeatedly see the problem: - xmms applet installed on gnome toolbar - start xmms - set as "sticky" and iconise This problem continues after shutting down xmms / removing xmms applet. Starting xmms any way (command line, etc) still causes it to not be visible (except in the desktop pager) when it gets de-iconised. Temporary fixing by removing .xmms files (not sure which one[s] in particular need to be deleted). (I noticed this on RH6.1, but haven't raised it as a bug)
I can't reproduce this here; I start the xmms applet, then start xmms, and I can iconise and de-iconise it; and it returns to its previous location.