Question: Multiple Threads in maple

Hello all,

I really don't know what is going on with my code but I think I can use some help. I'm new to Maple and to parallel programmimg. What I would to understand is why the following code is simply not working.

evList := seq(seq([i,j],j=i..6),i=1..6):
M := Matrix(6,shape=symmetric):
integMult := proc(kIni::integer, kFin::integer)
  local i, j, k, l, kk;
  global evList, M;
  for kk from kIni to kFin do
     i := evList[kk][1]:
     j := evList[kk][2]:
     M[i,j] := Matrix(3*n,(k,l)->evalf(int(expand(N[i][k]*N[j][l]),x[1]=0..a,x[2]=0..b)));
  od:
end proc:
Start(null, Task=[integMult,1,10],Task=[integMult,11,21]);

When I consider one single Thread (i.e. 1 to 21), it works like a charm. But the code written above gives me a kernel lost. I don't know if it is the shared variable "M" (matrices of matrices) or if it is the shared parameter (vector of vectors) , or both. But I've tested duplicating both and nothing different happens.

Can anyone help me?