I explain you the problem, you are trying to mine with Phoenixminer that he is not able to mine ETC yet correctly with Cards of only 4Gb... Phoenix or Claymore are not developing normally their miner, you should think to change to another miner that is newer and is able to do it. Look for someone that has algo been working with the last drivers... in your case you need also that because the 5500XT is a new card.

You should make a try to lolMiner for example… he has also implemented the Zombiee mode that Will allow you to mine ETC until new DAG switch