Sorry it took me so long to reply. I took her in to the vet immediately following my last post. Her verdict was the dog has allergies which causes her to get flaky skin if untreated. She said that this caused problems in her ears as well by leading to a yeast infection. Anyay, she got a hormone shot to cut down on the irritation and some solution that I've been putting in her ears twice a day. The ear flopping ceased immediately after visiting the vet (except for when I put the drops in...she hates that!)
Thanks for your advice and encouragement, everyone.