I am trying to write an application which automates one of UI based 
application written using Windows forms.But I am facing some issues.

a) AutomationElement.Fromhandle sometimes throws an exception sometimes when 
the application is initializing .
b)AutomationElement.FromHandle called from worker thread sometimes hangs and 
will not give properties correctly (like Automationid) .I read somewhere it 
will work only from main UI thread.
c)Is there a way where I can make a non blocking call to 
InvokePattern::Invoke. When InvokePattern::Invoke fires a event which 
launches another modal dialog, enumerating controls from worker thread doesnt 
seem to work.