I had the same issue. Your best bet is to download xport3 com port splitter. I lost track of thread I had posted but I will try to explain it.
Select a com port in the Delorme Serail em program. Then in XPort select that as the com in port. Then select a com output port.
Then go into Iguidance and take it out of Auto com port mode and manually select the com port that was the same as the out com port in xport3.
I don't remember all the menu names word for word so I apologize.
Even after doing this my earthmate still works erratically but it works most of the time. Down the road I am going to replace it to a newer sirf receiver.