I've had Google Earth installed for several months with no issue, but a couple of days ago a disk image for it has been mounting and then unmounting itself. I didn't download any update, and I hadn't used the software for a few weeks, so I don't know where the disk image came from. When it happens it will mount itself and open the window with the install shortcut and then it will go away after about 3 seconds. I can't find where the disk image is on my HDD and now even after I've opened Google Earth it keeps happening. It maybe does it about once an hour. Any suggestions as to how to stop this?