Loss of cordination while crawling

My 9 month old has been crawling for about 3 months now, and just flies around the house. She's a big girl for her age and usually a very well cordinated little thing, she hardly ever falls no matter what it is she's trying to do. Yesterday afternoon my husband was watching her while i was at work and noticed she was falling on her face alot while crawling, my mother in law was over and noticed it too. As the evening went on she seemed to snap out of it and wasn't having any trouble by the time I got home, but this morning she fell on her face while crying tried to get up and went right back down, hit her head and started crying. This might not be unusual for a baby who just started crawling but she really does have pretty good motor skills. I've been trying to look in the baby book about inner ear infections, but haven't really found anything. It's probly just nothing but I thought maybe someone else had noticed it in their child.