[amsat-bb] LVB Tracker not playing well with others

I picked up a LVB Tracker at Dayton last year and am just now getting it set up. No problem calibrating it to the G-5400B. All controlls work as expected. I connected the USB cable and loaded the drivers per the FTDI documentation but am having issues. As soon as I access the port from  Hyperterminal or SATPC32 I get a short "bluescreen of death" and the laptop re-starts. Internal inspection doesn't show anything obvious. I have not tried pulling the USB and installing an RS232 chip. I have tried un-installing and re-installing the drivers and get the same results even with a different PC. Any ideas?   Thanks Dave Julian WB9YIG