Dan,
It seems that this is a fairly common issue.  Below are links to discussion forums covering the same topic.
Basically, something is corrupted on that computer's
installation.  You will probably need to uninstall your drivers
and reinstall them.  If that does not work you might need to wipe
your computer of all NI references (even the registry) and reinstall,
and if that doesn't work... We won't go there yet, but you can guess
what is next.
http://forums.ni.com/ni/board/message?board.id=170&message.id=83456&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=170&message.id=129452&requireLogin=False
I wish I had better news,
Lorne Hengst
Application Engineer
National Instrumetns