The most frequent bug report was that NaroCAD crash at startup. The reason is that it did not find OpenCascade. From scratch I've thought that is not happening, but it seem that it does.
Just if you will want to use 1.2PRE installer and you don't have installed OpenCascade, please download it from here: http://www.opencascade.org/getocc/download/ (registration required). If supposedly it still do not start with your machine, you may need to download Visual C++ Runtime 2008 SP1.
NaroCAD installer comes with a mini distribution of OpenCascade, but seems that adding extra code features to current codebase may increased the dependencies and make it to not be enough what is bundled.
I still work on this issue and I really hope to be solved tomorrow.