This is not normal behavior. More specific information about the kind of behavior are you experiencing whenever it does not work could help find a solution.
Without more information it is hard to say what is happening but here are some ideas:
1. Bad IMAQ installation. Try uninstalling and reinstalling NI-IMAQ. You may also want to upgrade to the latest version of NI-IMAQ.
2. There may be dificulty interfacing with your system. You may try the card in a different machine or look for an update to you BIOS from your motherboard manufacturer.
3. The card may be damaged. If you continue to experience such problems you may want to Request Support and posibly send the card in for repair.
Hope this helps.
Regards,
Amaury Rolin
NI Applications Engineer
