wrong results when sync started not from scratch

Incorrect data in db when sync was first started to some block num and finish without error, and then sync is started once again to higher block number. For example:

1. hive sync --test-max-block=1500000 --database-url=postgresql://marcin:marcin@127.0.0.1/hivemind2 --steemd-url='{"default" : "http://127.0.0.1:8091"}
  # sync will finish correctly on 1.5m blocks
2. hive sync --test-max-block=5000000 --database-url=postgresql://marcin:marcin@127.0.0.1/hivemind2 --steemd-url='{"default" : "http://127.0.0.1:8091"}
  # sync will continue from 1.5m to 5m blocks but rshares, children and other data are not valid - verified with our tavern tests for 5m blocks