Dear Marc,
after playing around with version 0.10 for a while, i found out the following:
1. It crashes, when you convert a single file
2. It does not crash in batch mode
3. It does not crash when you check "Force OMG media type"
It does not crash either, when you use the HiMdRendererWin.exe from version 0.07, so the problem is most probably in the GUI.