The version of the Q3 2008 SP2 assemblies is 18.104.22.168. I would suggest that you uninstall all instances of RadControls for WinForms and reinstall Q3 2008 SP2.
If that does not work, it will be best if you open a new support ticket and send us a sample project that demonstrates the issue. This will allow us to identify and address it.
the Telerik team