Not importing tags in different hierarchies with same name

I did an export of a big vocabulary, then imported to another system. This operation went easy, but I saw that some items were missing.

Investigating, I saw that in the .xml file the items are in, and probably that's because there was, independent of tree depth level, the same name for other trees ramifications.

Example:

A
+-B
+-C
D
+-C
+-D
+-E

The A-C is imported, but the D-C not, neither D-D.

In my case, it's very common cities that have the same name, but in different states; and also a city that have the same state name.

Thanks for attention.