Go into MAX and see what versions of NI-VISA and NI-SERIAL you are running. We have had lots of problems matching up LabVIEW and the correct versions of these (especially with RT). LV7 has some problems with older versions of VISA and Serial and LV6.1 has problems with newer versions of them. And once you load the newer versions, you can't go back again. Even uninstalling the new versions and then installing the old versions doesn't work.
Rob
