You have version 5.01. Although it will normally talk the NN3D it can be problematic with the communication freezing. As I said before, version 8.01 came out back when 2.11 came out for the NN3D. I highly doubt downgrading from 2.13 to 2.11 will accomplish anything for you. I suspect that the NN3D is taking over talking to the FAX30 and this is why the PC can't talk to it with the NavNet on. The FAX30 is designed to be used with a Navnet or a PC but not both at the same time. If the Fax30 works with the PC then it is functional. You can either remove it from the NavNet network and use the PC, or send the unit in for software update so that it is up to speed to talk to the NN3D. Because you have 5.01; there isn't any hardware upgrade required so that is good news.