Instability of test de step_3 D8 between 32- and 64-bit Windows

Test de step_3 D8 produces different results on 32- and 64-bit binaries on my machine (CPU i7-4790, Windows 7, vc10 Sp1):

32-bit: shape produced after loop-bak is bad (Intersecting Wires)
64-bit: OK (reported as improvement)