Alternatively, HD Writer could just be telling lies.
No problems with playback - it doesn't look to be dropping any frames.
Conceivably it could be dropping 8 frames per second taking the playback down to 17fps but I don't think so.
Must remember to check the "don't tell me again" box to stop it warning me every time I play something back.
At least I can import and play videos and with a bit of luck edit them as well.
I shall be looking at other editing packages though.
Still photos indoors are nearly as good as my Sony K750i mobile phone so I won't be selling my Nikon D40X any time soon.
Cheers
LGC