Hmm, I've found a new bug in the latest version of NeroMix. I encoded a playlist of WAV files into MP4 using the HE AAC encoder. The filenames were in the format Artist - Track# - Title. It looks as if the program has SOME sort of naming convention recognization, as it tried to tag them with this information ( I don't know what tag format they are using here, but NeroMix recognizes it). Anyway, I get unrecognizeable characters in the track names when played by NeroMix, along with the Artist and Title info. I right clicked the tracks in NeroMix and selected "Selected File Properties", and the bug is plain as day: the program is adding bad characters to its tag info. This is quite possibly simply a bug in recognizing how the source files are named, who knows, but my method is very common.
Edit: Ah Ha! In the general settings, the program gives the option to convert file names to tags, but there are only three options: No conversion, To 'Title - Artist', and To 'Artist - Title' (the default).
Looks like they need to add some user configurable options to this as well, this is VERY rudimentary. Also, there is no way to edit this badly tagged information. Finally, in the Selected File Properties dialog box, the file dates and time are listed as 31.12.1969 18:00 , which is clearly WRONG!