Steps to reproduce:
-- Open any BPEL file 
-- Create a new BPEL variable and choose a type from a schema from BPEL Global Catalog. 
-- Close the dialog and open it again. 
-- The dialog doesn't restore tree selection. It has to select the type, which the variable has. 

My superficial analysis shows that the tree searching algorithm works fine. But there is another more serious problem. Unlike any other XML models, which have single instance, a new instance of model is created for modes from Global Catalog each time they are requested. 

It leads to impossibility of standard comparison. Two schema components can represent the same object, but they have different instances because they are located in different model's instances. 

I don't know what is the reason for such behavior and if is has been done intentionally. But it looks strange anyway and deserves to be investigated separately.