I am using Mac OS 10.6.4. I have a MacBook Pro 2.53 GHz Intel Core 2 Duo, 4GB RAM. I have had Google Earth running on this computer, but tonight it is crashing on startup. I have removed /Library/Application Support/Google Earth and /Library/Cache/Google Earth and the program several times tonight. I have downloaded v.5.2 twice or three times and reinstalled. None of this seems to fix the problem. According to one of the "Fix Mac Errors" pages, I've stepped through the items one-by-one, except for turning off atmospheres, which I can't do since the program won't load. My graphics card software is up to date. As I said above, Google Earth has been resident on this machine for more than a year and has worked fine until tonight. I'm a semi-PowerUser out of tricks. Any suggestions?