The 1200 family cards have some special properties different from the common E serials. It was ignored.
The following is the reason that causes the problem.
Unlike other boards in differential mode, for the 1200 family of data acquisition boards (DAQCard-1200, PCI-1200, Lab-PC-1200, DAQPad-1200, and Lab-PC-1200AI) the channels names of the four differential channels are 0, 2, 4, and 6 as opposed to 0, 1, 2, and 3. So, in your scan list you have to specify (in descending order) "6, 4, 2, 0" for your four differential channels.
The patch is available in the ftp://ftp.natinst.com under the name Biobench12P.exe.