Other authors CAN simultaneously edit a shared Word file in SkyDrive

I'm sharing an editable file via SkyDrive. I am the owner of the file. As I edit the file on my end and another person has the file open in Word simultaneously, that person sees dashed lines appear around the area I'm editing as do I. If you mouse over those lines, you see, "To avoid conflicts, other authors cannot edit in this area until you finish editing it and upload to the server." However, the area is not locked for editing. The other user can indeed click in the same area I am editing and also edit thereby creating annoying conflicts that need resolution. Why is this happening?