inconsistant result from "null"

I used "null " to solve a homogenious equation which is a determinant of a matrix, but i found when the determinant is changed a little bit, i got very inconsistant result, are there any way to get a more consistant result? the following is cut and paste from the real runing program: When the root of the determinant is equal to 0.527785592374495 + 0.118279569892473i, null(WW)=

0.000000000000000                       0.000000000043649                     
 -0.776234180889516 - 0.630444681489806i -0.000000000002771 + 0.000000000000302i
                  0 - 0.000000000000000i -0.000000000028390 - 0.000000000082173i
 -0.000000000002374 + 0.000000000001462i  0.226282459254081 - 0.974061727322209i

When the root of the determinant is slightly changed to 0.524178053258712 + 0.118279569892475i, null(WW)=

   -0.000000000043399                     
   -0.000000000001090 + 0.000000000000128i
    0.000000000028560 + 0.000000000082160i
   -0.220919301866939 + 0.975292090638812i

So are there any way to get a more consistant single solution ? because the roots changed gradually in each for loop, I require the solution of null (WW) also changed gradually. a abrupt change of the solution from null(WW) will result in a void calculation