I am also have this problem. I have six rigs that were all mining since November when 4 gig opened back up and I switched from claymore to Phoenixminer. Although the hashrates have been decreasing over the past month, starting this morning they all skyrocketed back to their maximums I’ve ever seen. About 30 per card. However nanopool shows them all off-line and rejects transactions. I have been using Ethos with Phoenixminer 5.4b. I upgraded 1 machine to 5.4c with the same issue.  I looked at the miner log and it looks like there’s something going on with the Epoc 390. Is this the end of mining ETC with 4 gig cards?

Thanks in advance to anyone who can offer me advice,

Ken