Hi,
so your first problem is sloved,now what may be the solution for your next problem is that you have made the main VI front panel as dialog or stay in front,by this what happens is you will not be able to load any other panel,so make sure you have the stay on top or modal for all the panels or else for none of the panels,by this you will have only the panel which you want in front as stay on top so till you close that particular one you will not be able to go to the next,this will solve your problem i hope.
cheers
vicky