This is what I expected where the wallet.dat file should be located. But even before the crash, I wasn't able to see the wallet file in the application support folder. Out of curiosity, I created a new user in the mac login option and tried to run protoshares there. There it worked fine and didn't quit, but even there I cannot find the wallet.dat file in the application support folder. Even if protoshares was to worked fine, I wouldn't feel comfortable to have value stored in the wallet.dat file not knowing where in my computer it is located.