I had the SAME problem and it seems to be the DRM. However, now it seems i have a reliable way to get into the game:
1. Delete the folder 'Documents (And Settings)\All Users\Application Data\SEGA Corporation'
2. Delete the folder 'Documents (And Settings)\YourUserName\Application Data\SEGA Corporation'
3. Run the game (APGame.exe). The DRM screen will show up and will request you to input the game key
4. Input an INVALID game key. For example change one symbol, or type in some random line (would be even better to make it shorter than the real key just in case)
5. It will show you 'the key is wrong'.
6. Now Input the VALID key. Your key.
7. Strangely enough it still shows for me 'The key is wrong'. But when i type the VALID key in again it works ok and gets to the next screen.
8. In that 'screen' you have two buttons one of which is to RUN the game.
Unfortunately after you exit you have to do the whole procedure again. Still. Worked for me.
The ONLY way the game starts for me is when i get TWO buttons in the DRM screen after the key entered was valid. If i enter the key right immediately the game starts with no buttons to click. And it doesn't start and shows the same error you posted.
I don't know if it'll work for you. Because my game directory is all messed up now. I've tried to move configuration files all around, and tried to use a ... noCD... Two noCDs. They didn't run as well. Besides it's WinXP SP3 x86 i have installed, not x64. Give it a try.
