spec import_inheritance data

Dear experts,

I m trying to export and import spec that has inheritance relationship. but after importing spec data, inheritance relation is getting deleted.

please advice me how to import data having inheritance relationship.

1> I tried using [restart inheritance]button to reload but nothing happens then

2> I tried [inheritance acitve/inactive]button to get back the relationship. and i got the the relationship but my instance in the property is

not the same. a new instance is been added.

does anybody has gone throught with this situation? please advice is you have an solution.

thanks in advance.