a problem with analog input in matlab

Hello.
I have a small problem with the ‘Data acquisition’ toolbox. I am trying to get an input from a generator with a 5volt pulse. Unfortunately, matlab is identifying it as a 10.6 volt, even when I don’t generate the power, which means that by using the analog input toolbox I get always the same voltage all the time, accept when I play with the voltage, then I can see that there is a change in the voltage, and then it goes hack to 10.6V. The weird thing is that when I try the ‘daqscope’ demo, it shows me the true voltage.
This is all done after I defined the ‘nidaq’ device and the right channel.

I can’t understand what’s wrong with it.
If anyone could help me, I’d be really thankful!
.