After pairing, the SD1000s won't connect any serial devise to any other serial devise. I've been using the SD1000s for months with a Trimble TSC2 and a Trimble 5600 robotic total station. One of the units started acting funny so I bought a new one to replace it. Using the units, I cannot connect to the 5600 or to any other device. The TSC2 will connect to the other devices with a serial cable but not with the SD1000s. Any ideas or things I can try to get them to work?