I am having problems with my E-M1 acquiring focus on small things that are some distance from the background, for example a small flower or blade of grass. Even items that completely fill the target box will often fail to focus. If I prefocus manually, it will usually acquire good focus if it's fairly close to being in focus. Switching to the small focus target does not seem to help very much. Both the 25mm and 12-40mm lenses behaved the same. I hauled out my old Canon 20-D to compare, and it does vastly better. Is this normal for the camera, or do I have a defective one?