Hi and welcome....
You can contact the developer using this email address.
How to use the Mac App Store help here.
Topic : The Mac App Store Discussion, what is it for?
Carolyn27" iMac 3.2GHz i3 MBAir iPad iPhone 3GS 4.2 iLife iWork / AirPlay / ATV2, Mac OS X (10.6.6), QTPro Intuos Epson Olympus Airport JBL
Thank you for contacting Aspyr Technical Support!
Go into your Macintosh Hard Drive and select your Applications folder, you should see a Call of Duty 4 Application icon. Right click on the icon and select Show Package Content then select Content. You will see a Call of Duty 4 Multiplayer icon, double click on the icon to launch the multiplayer app. When at the main menu select Options then multiplayer options. Go to the option to where it ask you to input your CD key and click on one of the empty bars and your CD key will generate. Once it has popped up, select Verify key and then join a game and see if you get the same message. If you do, delete your .plist file in your Macintosh Hard Drive and go into your Home folder (small house icon)>Library>Preferences, find the file called com.aspyr.callofduty4.plist. Drag that file over to the trash then empty it out then relaunch the game by Show Package Content again.
LION DOES NOT ALLOW ACCESS IN THE FINDER FOR THIS DIRECTORY FOR USERS TO GET TO LIBRARY
Please press cmd+shift+G to bring up a search window and type in '~/library' to access this directory.
Feel free to contact us with any further issues or concerns.
Aspyr Technical Support
I've tried the entire sequence from Aspyr Technical Support twice, and I've tried deleting the application and reinstalling. Are there other options? Is there alog file that should be reviewed?