Game Data loading work around
 

One of the problems that I have constantly been running into when creating interface pieces is that the gamedata information is populated after the interface piece is drawn. This is why OnShow rarely works for interface pieces that are always on. I found something that appears to work. Use OnHide with the eq2ui_hud_zoning.xml. The interface actually loads while the zoning window is still up. So if OnShow for a particular piece doesn't work try using the OnHide of the eq2ui_hud_zoning.xml.

I can see one possible major problem with this solution. If your using several pieces from different authors who all us the same device, only one of them will work.