Ever since having major problems with Boot Camp (wrong CD type, as well as installing it over OS X) and then finally just now getting rid of that portion of the hardrive that was partioned to Windows, I thought all was back to normal with my Mac but something odd recently started happened. When I turn my Mac on, instead of showing the grey Apple, it shows a gray blinking image of the world. And it shows nothing more. I have to hold option while booting up and select Macintosh HD in order for it to load OS X. Any help on how to get rid of this?