I've created a custom property type derived from PropertyData (stored as LongString). It works as expected except wen a page is copied or exported-imported, in which case the property value is cleared. Any clues to what might be wrong? Thanks in advance!
Ah, of course... The export (and apparently copy too) calls ToString on the property value to serialize it, and I was returning a type that didn't have a ToString implementation leading to the use of the standard ToString (which only returns the type name).