OPenFoam3.0+ on windows 7: blockMesh killed when using more than ~1M cells

Hello,

I have a problem with large meshes more than 1M cells. I'm using OpenFoam on Windows 7. I copied the cavity tutorial to my working directory and gradually increased the number of nodes. When the resulting mesh is larger than about 1M cells, the process is killed without an error message. I checked that ulimit is unlimited and checked through task manager that there is enough memory available. Does anyone have a clue?

Alexander