Digital BW, The Print

I am doing a fast tour through QTR to get a feel for the process and I've hit a snag I can't get past.  I've scanned the 21 step test wedge with the value scale I've developed into Photoshop and measured the Lab values of each tone patch.  I've then opened the curve in the curve editor and  entered the values in the linearization boxes (there are now 40 boxes instead of the 21 shown in the Guide illustration) from upper left, across the top, back to the left side of the second row,etc until my last value is in the first box on the third row.  I've tried it 0-100 and 100-0 but I always get the following message: Invalid linearize curve -- not constantly increasing.  Curve Creation failed.

Any help on where I'm going wrong at this step would be appreciated.  Thanks.