Hi Zorro,
There should be no problem in using the tasks and scales that you originally saved in your project. Do you have multiple DAQ boards in this system, such that the board you are intending to use now has a different device name in MAX? For example, the card could now be displayed in MAX as Dev2 when you originally programmed it with a device name of Dev1. Also, if you open up test panels within MAX for your device do you still get 0V readings on all of the input channels in question?
Regards,
Andrew W
National Instruments