Hello Andy,
We recently found an issue where a small number of FW-7344 boards
were shipped without having their serial numbers programmed into the
onboard memory. These boards work fine with older versions of
NI-Motion, but are not recognized by NI-Motion 7.0. It sounds like you
received one of these boards. If that is the case, then the board will
still not show up when the other board is removed. If you find
this to be true, then I recommend that you contact National Instruments
to RMA the board. If that is not the case, then let me know.
Have a great day,