setup of MikTex 2.9.5105 fails, it fails always at a different percentage (randomness), but it does always fail

ros 0.4.7RC1
MikTex 2.9.5105 (it's in rapps)
SHA1: 8a0797f119d796ff80adfab99945e76e6883609f
Make sure to use that exact version

the setup of MikTex failed for me, it always fails differently, but it will always fail.

I double-checked: That very same setup completes fine in 2k3sp2 and XPSP3

The first time I got a failure, it looked, like this, but the symptom changes with every test-execution
0.4.7RC1 when it wants to parametrize initexmf process.
following sounds interesting in setup.log

353316 [basic-miktex-2.9.5105.setup]: initexmf: --common-install=C:\Programme\MiKTeX 2.9: unknown option

Maybe it has issues parsing the command-line options somehow (double-minus)?
setup.png