Problem with patterns on XP under limited user rights

I need to automate testing scenario which tests our application running under limited user rights, but I'm having issues with patterns on Windows XP. I'm able to receive all elements as if the application was running under admin account, but for some reason not all patterns are available, for example ExpandCollapsePattern for TreeView items. GetCurrentPattern method always returns null on these elements.

The problem only occurs on XP machines and only if my automation app is running as admin and tested app under limited user (if both are running under limited user then it works properly). Any idea what might be wrong?

I'm using unmanaged UIAutomation API via UIAutomationClient interop wrapper in C#.