I can successfully display a nested list/tree store where the data is loaded via ajax. But I'm having problems adding items to the store, with the display of the tree nodes getting very confused (duplicated children etc). Looking on the web I can see lots of people having problems figuring out how to dynamically alter nested lists/tree stores, but I've not come across any good examples of how to do this. Does the absence of such examples suggest that there are currently bugs in the implementation of these features that make it difficult to write such examples? Or do examples exist and I'm just looking in the wrong place?