Hi Henry,
Thanks for your interest in Syncfusion Products.
I am afraid that I can’t reproduce the issue. Since we use AppStateSerializer with SerializeMode.XMLFile and persist it for saving the Bar state and while loading we use LoadBarState() method to restore the Customized settings, so there is no need to use the property AutoPersistCustomization = true and AutoLoadToolBarPositions = true. Please refer the sample attached below where the xml file is stored in bin->Debug folder.
Here is the sample for your reference.
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=MainFrameManager_Menustate-204131882.zipPlease Let me know if you have any further concerns.
Regards,
Arulraj.A