I changed the obi dial plan string when I first got it so that asterisk handles everything. All the ** codes were removed.
The normal Line 1 is connected to a single Panasonic cordless phone. Line 2 is connected to a string of corded phones in the house. At first, I thought it was RFI on the Panasonic, but the problem went away on the Panasonic and moved to the corded phones when I physically switched the cables.
After the problem went away, I switched them back to the original position and still no static on either line. The problem went away when that call came in. I am worried that there might be a cap inside the unit that is drying out.
The only thing I can do now is to wait and see if it happens again.