Hello gunking,
Thanks for your post!
It sounds like you are having an intermittent
problem with using your DAQmx assistant. Does the error that you are seeing have an error number associated with it or is it a "windows" error. Does this happen any time you use a DAQ assistant and in any program? What you may want to do is try rebuilding the DAQ assistant so delete all the assistants in your program and then rebuild them. Also when you see the two instances in your task manager if you end only one of the runtimes does it allow your program to function correctly. The last step would be to possibly reinstall the driver as there could be a windows conflict. You are using LV 7.0 so you would need to install DAQmx 8.1. You can get to this download by going to drivers and upgrades on the ni.com website.
Drivers and UpgradesPost back with more findings and let us know if you have any other questions!
Cheers!
Corby_B
http://www.ni.com/support