As a civilian AFF instructor I recently had the opportunity to sit in on a military 1st jump briefing. As the Instructor went through the familiar points on canopy control, he announced that if the canopy is left to it's own devices, the canopy will turn and run downwind.
The canopy they use is a square 360 much like a small Tandem canopy.
Frankly I was amazed at this piece of information and tried to explain that as far as I knew there was no way a canopies flight could be affected by wind direction, only its apparent ground speed would be affected.
If anyone can enlighten me otherwise I'd be very interested.
I have a feeling it's a hang over from round canopy briefings. With almost no forward speed they will descend down wind.