I've had that happen too. But when just the right title pops into my head, I've noticed that's the pic I'll work on longest and hardest ... don't know why, but the words that go with a pic are very important to me. That being said, I recently took a page out of Mike Savad 's book and posted an image that is mostly descriptive to the location and subject. We'll see if it makes any difference to Google over time, I guess.