[Limdep Nlogit List] Grouped data error message

[Andreas C Drichoutis]

Hi all,
 
I'm estimating a grouped data model and I get the below error message along
with a normal exit from iterations status. Are results trustworthy?
 
Thanks, 
Andreas
 
--> grouped ; lhs=VNL ; rhs=ONE, TAST, NUT, WWEEKH, STR,
    NFLX, PHDM, ISMED, ISELSE, ISFRIEN,ISNO, PLANNER,WEST,EAST, SOUTH,
    NORTH, BH,GH, EXER, NKN,NI,EFF2,GEND,AGE, EDUC2,EDUC3,
    INC1,INC2,INC3,ALWOFT, MED, OV,OB, HORIZON
    ; limits=0,2,3,5,8,13,21,36,60 ; KEEP=FITWTP2 $
Hessian is not positive definite at start values.
Error:   803: Hessian is not positive definite at start values.
B0 is too far from solution for Newton method.
Switching to BFGS as a better solution method.
Error:   137: Iterations: function not computable at crnt. trial estimate
Normal exit from iterations. Exit status=0.
 
+---------------------------------------------+
| Limited Dependent Variable Model - CENSORED |
| Maximum Likelihood Estimates                |
| Model estimated: Aug 09, 2006 at 10:50:06AM.|
| Dependent variable                  VNL     |
| Weighting variable                 None     |
| Number of observations              262     |
| Iterations completed                 40     |
| Log likelihood function       -542.1200     |
| Censoring Thresholds for the 10 cells:      |
|      Lower   Upper     Lower    Upper       |
|  1 *******     .00  2     .00    2.00       |
|  3    2.00    3.00  4    3.00    5.00       |
|  5    5.00    8.00  6    8.00   13.00       |
|  7   13.00   21.00  8   21.00   36.00       |
|  9   36.00   60.00 10   60.00 *******       |
+---------------------------------------------+
+---------+--------------+----------------+--------+---------+----------+
|Variable | Coefficient  | Standard Error |b/St.Er.|P[|Z|>z] | Mean of X|
+---------+--------------+----------------+--------+---------+----------+
          Primary Index Equation for Model
 Constant    -8.482913005       10.233783    -.829   .4072
 TAST         5.478935157       4.9333578    1.111   .2667     .97328244
 NUT          2.177748079       3.8330831     .568   .5699     .95038168
 WWEEKH       .1680148164   .57624526E-01    2.916   .0035     17.062977
 STR          .8091784428       3.3797176     .239   .8108  .72519084E-01
 NFLX        -7.947525292       2.5603588   -3.104   .0019     .18702290
 PHDM         4.183857111       2.5979839    1.610   .1073     .12595420
 ISMED        .7586809924       2.9977169     .253   .8002  .76335878E-01
 ISELSE      -3.926185490       4.6233206    -.849   .3958  .34351145E-01
 ISFRIEN     -.3896667449       2.0310790    -.192   .8479     .20229008
 ISNO         2.533267410       2.2699547    1.116   .2644     .17938931
 PLANNER     -3.313984298       2.6051747   -1.272   .2033     .76717557
 WEST        -5.941326081       2.5333251   -2.345   .0190     .29770992
 EAST         2.170737846       3.1197779     .696   .4866     .10687023
 SOUTH       -1.999043292       2.6000425    -.769   .4420     .21755725
 NORTH       -4.495901729       2.6671186   -1.686   .0919     .20992366
 BH          -.8803782412       2.8059552    -.314   .7537     .11832061
 GH          -1.881621104       1.8778815   -1.002   .3163     .50381679
 EXER        -.9005623461       2.0039123    -.449   .6531     .25954198
 NKN          1.296717302       .65778032    1.971   .0487     5.5190840
 NI          -.6860157977       .71955480    -.953   .3404     4.5725191
 EFF2         2.095537087       3.1710858     .661   .5087     .69338422
 GEND        -2.860793117       2.5055022   -1.142   .2535     .32061069
 AGE       .4139288739E-01  .67178016E-01     .616   .5378     49.572519
 EDUC2        1.829472402       2.1265093     .860   .3896     .45419847
 EDUC3       -1.524310636       2.8037247    -.544   .5867     .29007634
 INC1         4.408267518       3.5997424    1.225   .2207     .22519084
 INC2        -1.285378004       3.5167576    -.366   .7147     .33969466
 INC3         1.958109458       3.2865041     .596   .5513     .34732824
 ALWOFT       3.913428558       1.7985271    2.176   .0296     .34351145
 MED          3.683483871       2.6087065    1.412   .1580     .11450382
 OV          -4.368004327       1.8488591   -2.363   .0182     .41603053
 OB          -.8965140373       2.2921617    -.391   .6957     .18320611
 HORIZON      4.820180890       1.5867367    3.038   .0024     .38167939
 
 Sigma        11.23682290       .64048764   17.544   .0000
 (Note: E+nn or E-nn means multiply by 10 to + or -nn power.)