4 Answers, 1 is accepted
What is your exact scenario?
If anyone else run into problems with nodes not being checked after post back, then make sure nodes are added during OnInit, not CreateChildControls, which seems to be too late in this case.
I am partially populating a load-on-demand tree that is toggled to be visible and hidden via AJAX. I perform the partial population in CreateChildControls. On the initial page load the tree is not visible (which is by design) --> AJAX toggle: it's visible and checked (good) --> AJAX toggle: it's hidden (good) --> AJAX toggle: it's visible but not checked (bad). I have the same problem when I populate the tree in OnInit. I fixed the problem by setting the tree's EnableViewState property to False, which I probably would have done while optimizing the code anyway.
Hope this helps someone.