James,
Unfortunately, I don't remember what versions of DAQmx and VISA I was using. I got so frustrated that I simply uninstalled all of my NI software and reinstalled only the driver versions that came with Measurement Studio (followed by the patch). That of course fixed the problem. I think that I can get by with those drivers for everything I want to do, so my problem is effectively resolved as far as development goes.
I do have a possibly related problem with running my application though. I built a Visual Studio setup project and installed it on a seperate computer, but the first call to CreateAIVoltageChannel throws a BadImageFormatException. That computer had the latest versions of DAQmx and VISA installed, so I tried downgrading them to the versions from the Measurement Studio CD, but that didn't help. I think that the uninstallations of DAQmx and VISA left some components behind. Are there known backward compatibility issues with later versions of DAQmx or VISA? I successfully ran my original application (before I started having license issues with Measurement Studio, though with somewhat newer versions of the drivers than those the Measurement Studio CD) on the same computer with the same versions of DAQmx and VISA though.
P.S. After downgrading the target machine didn't work, I tried uninstalling all of the NI software on it and starting fresh, but one of the uninstallations seemed to wreck Windows to the point that it wouldn't even boot in safe mode (not a big deal, just a pain).
