BMW have now washed their hands of it...................
The reason I ask about the power up, is because it can either come direct from the battery via a fuse, and thus the DVR (recorder) is live all the time (residual current), or someone (you/prev owner) has fitted a seperate fuse control system, which feeds many units, such as DRL, charging leads, Innovv, etc.
If it is the latter, these electronic fuse units usually have timers within them, which delay start-up and other things, and usually are programmable too.
The Innovv unit needs to see a permanent 12v connected to it in order to write it's files properly. So if you're connected via one of these units, and there are timings involved, the Innovv may not get its 12v correctly, thus messing up the writing of the video files.
I found this out the hard way, took me a week to find out the fuse unit was closing down just a few seconds too early, thus messing up the writing of the files. I extended the switch off time (on the fuse unit) from the standard time of about 7s, to 30s, and all was well.
If you don't fix it (and Innovv are very helpful), and fancy a ride down to south Cheshire, we can trouble shoot it.
Regards
Phil