JSTree and IE(7/8): all non-leaf nodes open after tree loading

i have some issues with JSTree IE(7 and 8): after tree loading, all the non-leaf nodes are open (the tree is loaded from a json data structure, with only one non-leaf node with the "state" object setted to "open" and all the other to "closed"). the same code work properly on ff, opera and safari.

here is the js code: http://jsf开发者_开发问答iddle.net/yuXxx/

and here is the json generated code (validated): http://pastebin.com/Zw1KYEK5

anybody could help me? tnx

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The above issue happening in chrome also.