BRepAlgo_Fuse problem

Hello,
I try to fuse 2 faces (2 square in the same plane) with the help of BRepAlgo_Fuse.
Squares are 10x10 and the second on is translated of D with respect to the first one along the x axis.

The result of this fusion amazingly depends on the value of D.
- With D = 5, the fusion is ok (image of the result at "http://steve.bourgeois.free.fr/Vrac/OCC/Fuse_Tran_5_Scucess.jpg".
- With D = 9, the fusion fail and if I display the corresponding wire, a hole appear (cf. picture "http://steve.bourgeois.free.fr/Vrac/OCC/Fuse_Trans9_Fail.jpg".

The code used to create theses faces and fuse them :

//Vertices of the first square
gp_Pnt E(0,10,0.0);
gp_Pnt F(0,0,0.0);
gp_Pnt G(10,0,0.0);
gp_Pnt H(10,10,0.0);

//Vertices of the second square
gp_Pnt I(9,10,0.0);
gp_Pnt J(9,0,0.0);
gp_Pnt K(19,0,0.0);
gp_Pnt L(19,10,0.0);

//Construction of the fist square
BRepBuilderAPI_MakeWire wireMakerb;
wireMakerb.Add(BRepBuilderAPI_MakeEdge(E, F).Edge());
wireMakerb.Add(BRepBuilderAPI_MakeEdge (F, G).Edge());
wireMakerb.Add(BRepBuilderAPI_MakeEdge(G, H).Edge());
BRepBuilderAPI_MakeEdge ME2b(F, G);
wireMakerb.Add(BRepBuilderAPI_MakeEdge(H, E).Edge());
BRepBuilderAPI_MakeFace faceMakerb (wireMakerb.Wire());
TopoDS_Shape B = faceMakerb.Face();

//Construction of the second square
BRepBuilderAPI_MakeWire wireMakerc;
wireMakerc.Add(BRepBuilderAPI_MakeEdge(I, J).Edge());
wireMakerc.Add(BRepBuilderAPI_MakeEdge (J, K).Edge());
wireMakerc.Add(BRepBuilderAPI_MakeEdge (K, L).Edge());
wireMakerc.Add(BRepBuilderAPI_MakeEdge(L, I).Edge());
BRepBuilderAPI_MakeFace faceMakerc (wireMakerc.Wire());
TopoDS_Shape C = faceMakerc.Face();

//Fusion of the 2 squares
TopoDS_Shape faceFuse = BRepAlgo_Fuse(B,C);

If someone know how to solve this problem...
Thank
Steve