Are you using the Redirector? Or BES,BIS? If you are using BES/BIS then you need to delete the Desktop Service Books

Menu>options>Advance Options>Service Books

Select and delete all service books entitled "Desktop[cxxxx]"

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If you are using the Redirector they are normal. If you are getting them in excess your encryption key might be out of date and you need to connect to the PC running redirector and generate a new one.