bulkloader: key ordering issue with --dump

Question

After creating a patch to resolve this issue, I am now experiencing this when attempting to dump my data:

[ERROR   ] [Thread-2] ExportProgressThread:
Traceback (most recent call last):
  File "/Users/matthew/local/opt/google_appengine/google/appengine/tools/bulkloader.py", line 1375, in run
    self.PerformWork()
  File "/Users/matthew/local/opt/google_appengine/google/appengine/tools/bulkloader.py", line 2117, in PerformWork
    item.progress_key = self.db.StoreKeys(item.key_start, item.key_end)
  File "/Users/matthew/local/opt/google_appengine/google/appengine/tools/bulkloader.py", line 1916, in StoreKeys
    repr(key_start), repr(key_end))
AssertionError: datastore_types.Key.from_path(u'Image', 6199L, _app_id_namespace=u'meh-instinct') not less than datastore_types.Key.from_path(u'Image', 6092L, _app_id_namespace=u'meh-instinct')

It seems that my keys are being selected for export in an unexpected order.

Any ideas?