jb,
Are you using panos in your sample,..are they showing up and just not the boxes? I've had some strange occurences using multiples xmls where a pluging added would make another plugin dissappear even though the were set up on different corners of the page AND had logical zorders(so I thought)., and also some trouble with actions not fully executing and stalling at DIFFERENT point of the commands,..and yet sometimes fully executing. I can only suggest, I guess, the obvious,..make sure your keeping all the plugins and they're visible(maybe don't rely on default settings but code them in),...and the not so obviuos, play with zorders,...thats how got lucky,..EVEN though the order didn't make sense(for me anyway),..or eliminate one of the plugins if you can and see if the remaining two return.
Rob