It looks like it's working with cgminer, and it doesn't work with bmminer.
But the problem with "Low worker difficulty ..." exists in both cases.
For example, I see maximum share difficulty 8074 for E9, while Mining Rig Rentals recommend "The OPTIMAL Difficulty range for this rig is 22,119 - 133k". (Port 4334 gives share difficulty 1 000 000, that is too high).
Mr. Con Kolivas, can you check it (or give us some advice) ?
yes i can confirm if you rent on miningrigrentals a rig whit diff +1m it's work on port 3333 and perfect on port 4334 ... if you rent a mining rig under 1mil diff ... you have difficulty on port 4334 (too high diff error) and on port 3333 error too low diff... :/