Bug reduce images

If I want to reduce a image which is on a wall, it 'flops' away very far, sometimes over 10 blocks. And that's everytime the case. But there's another case, only happens sometimes. The item flops eg. 10 blocks to the right and at the moment it falls to the floor, it's away. It appears 10 blocks at the left site from the place, the image was hunging. This Bug could be enhanced, because sometimes the items flops through other blocks. While you embellished your house and be on the search after the right image, you must place and break images often and it's irritating to search the broken image-items after that.