Mac Crack Attack version 1.1 and greater has an auto-update feature that checks if a new version is available at sourceforge. For the release of v1.1.0 a bug found its way into the auto-update code (basically one line of code was missing that checked if on-line). Version 1.1.1 was released soon after this was discovered, this version should not have this problem (if you experience this problem with version 1.1.1 please contact the author). To permanently disable version checks add (inside the "dict" tag)

<key>version_check_disabled</key>
<true/>

to ~/Library/Preferences/MacCrackAttack.plist after the game has been succesfully run once to create this file.