QTR-Quadtone RIP

I've been trying to create a set of curves for a new paper on my Epson 3880, but the initial curve never becomes a straight line after linearization. Isn't it supposed to become a straight line?

I read all the docs and did the following: printed the ink separation chart and calculated my ink limits for K, LK, and LLK inks. (The numbers were K: 55%, LK: 46%, LLK: 14%.) After inserting those numbers into my new curve file and installing the file, I printed the Step-21x4-random.tif file and used my Datacolor 1005 spectrophotometer and Spyder3Print software on a Mac to read the swatches. After running the resulting file through QTR-Linearize-Data, the result came out as a curve.

Step	Dens	Lab	A	B	
0.00	0.045	96.09	0.00	0.00	-                             b                          L  +
5.00	0.075	93.51	0.00	0.00	-                             b                         L   +
10.00	0.100	91.44	0.00	0.00	-                             b                       L     +
15.00	0.125	89.39	0.00	0.00	-                             b                      L      +
20.00	0.155	86.99	0.00	0.00	-                             b                     L       +
25.00	0.188	84.45	0.00	0.00	-                             b                   L         +
30.00	0.225	81.61	0.00	0.00	-                             b                 L           +
35.00	0.280	77.57	0.00	0.00	-                             b               L             +
40.00	0.318	74.92	0.00	0.00	-                             b             L               +
45.00	0.363	71.82	0.00	0.00	-                             b            L                +
50.00	0.415	68.36	0.00	0.00	-                             b          L                  +
55.00	0.477	64.41	0.00	0.00	-                             b       L                     +
60.00	0.542	60.49	0.00	0.00	-                             b     L                       +
65.00	0.615	56.36	0.00	0.00	-                             b  L                          +
70.00	0.688	52.44	0.00	0.00	-                             bL                            +
75.00	0.782	47.63	0.00	0.00	-                           L b                             +
80.00	0.877	43.15	0.00	0.00	-                        L    b                             +
85.00	1.047	35.92	0.00	0.00	-                    L        b                             +
90.00	1.282	27.35	0.00	0.00	-               L             b                             +
95.00	1.675	16.14	0.00	0.00	-        L                    b                             +
100.00	2.138	6.60	0.00	0.00	-  L                          b                             +

LINEARIZE="96.085 93.5125 91.435 89.3875 86.9875 84.455 81.6075 77.57 74.915 71.8225 68.355 64.405 60.4925 56.3575 52.4375 47.6275 43.1525 35.9175 27.3475 16.14 6.5975"

Is this the way it should be? Did I do something wrong? Am I mis-interrpeting the word "linearize" here?

Any help/explanation would be greatly appreciated.

Many thanks,
Dave