since that's what i have in my wife's car, and what i originally wrote the script for, and i still use the script every time i make a new Dashcam Chronicles video, i wouldn't expect any issues using the script with videos from your cam.
Wmp can't play multi track video but VLC (VideoLAN is the name of the company, not sure what the C stands for - doubt it's "Corp" since it's open source and was originally just an informal group of people) plays it just fine. the fact that it plays properly in the blacksys program means the files are probably fine. pretty much NO video editors (moviemaker, VSDC, VideoPad, kdenlive, maybe even premiere) can handle multi-track video, which is why i made this script in the first place. btw - windows movie maker is no longer supported, so you may want to consider uninstalling it since it won't get any more security patches, and switch to something like VideoPad or VSDC. both are free windows editors.
agree - it's got way more features, is way less intrusive, and to me, easier to use than WMP.