Thank you for writing.
Please find the answers to your questions below:
- I confirm that collapsing items for virtualized RadListBox is not working correctly. This issue will be addressed in the upcoming release (Q1 2008). Meanwhile you may disable the virtualization by setting the Virtualized property of RadListBox to false.
Thank you for bringing this issue to our attention. Your points are updated.
- I am not sure I completely understand your scenario. Could you give me a project that demonstrates what you describe or provide more information what control you are binding and what you expect to happen when changing ToggleState of some of its items.
I hope this helps. If you need any further assistance, please contact me.
the Telerik team