This is kind of an odd one. In some cases, the schema validation works as expected (same xmlns and schema definitions; no real change in element ordering, etc), in other cases, I see the following:
The cache-name and scheme-name elements are indeed valid. In fact, if you remove those elements and try to auto-complete the legal elements, nothing comes up.
Even when and forced the association between the schema and schema URI.
Nothing stands out in the idea.log.