classify() from classify.lib gives a different result after simple transformation

[steenpass]

> option(noloadLib);
> LIB "classify.lib";
> ring r = 0, (x,y), ds;
> poly f = x3y+xy4+y5;
> classify(f);   // this is correct
About the singularity :
          Milnor number(f)   = 11
          Corank(f)          = 2
          Determinacy       <= 8
Guessing type via Milnorcode:   Z[k,12k+6r-1]=Z[1,11] Y[k,r,s]=Y[1,1,1]

Computing normal form ...
   Arnold step number 19
The singularity
   x3y+xy4+y5
is R-equivalent to Z[11].
   Milnor number = 11
   modality      = 1
x3y+xy4+y5
> map phi = r, -x+y, x+y;   // this is a proper transformation
> f = phi(f);
> classify(f);                     
About the singularity :
          Milnor number(f)   = 11
          Corank(f)          = 2
          Determinacy       <= 8
Guessing type via Milnorcode:   Z[k,12k+6r-1]=Z[1,11] Y[k,r,s]=Y[1,1,1]

Computing normal form ...
// ** int division with `/`: use `div` instead in line >>        bb[rvar(x(1))] = x(1) - (2*gamma / (B - beta))*x(2);<<
// ** int division with `/`: use `div` instead in line >>        bb[rvar(x(2))] = x(2) - ((C - beta) / (2*gamma))*x(1);<<
   Arnold step number 24
The singularity
   32x5
is R-equivalent to Z[1,-4].
   Milnor number = 11
   modality      = 2
Initial condition failed: k>=0; r>=0; s>=0
k=1 r=-4   s=0
0
> 

Replacing '/' by 'div' in the mentioned lines as suggested (which should also be done) doesn't solve this.