Problem: Mx Extension implementing IPersistVariant is not persisted
When an Mx Extension implements IPersistVariant, the IPersistVariant_Save method is invoked when the document is saved. Under some circumstances, the IPersistVariant_Save method is not called and the extension does not have the opportunity to save anything to the stream.
The problem may be that the Extension name returned in the IExtension_Name property is longer than 31 characters.
Solution or Workaround
Change the IExtension_Name property so that a string with 31 or fewer characters is returned.