Analog output from NI 6014 card

I am using two National Instruments DAQ cards - NI-6014 and NI-6703. Both of them are to work in RT linux mode using Comedi drivers. While the Digital I/O are working perfectly well, with almost 100 microsec resolution, I have problem with Analog output (Analog input on NI6014 is working fine). For both cards, AO sets to some arbitrary value once I send in the command. Am I doing something wrong?

Ashok