Pokemon D/P/Pt Wild Pokemon Modifier

There is some kind of a problem I'm facing with all three of these games when I want to use the wild Pokemon modifier cheat.
At first all seems normal when I open the cheat database before starting the game, but when I go further down the list, the problem presents itself. The actual list of Pokemon I could catch with the cheat goes only from Bulbasaur to Hitmontop. On all three of the games, I face the same problem. When I check the XML-document that shows the actual codes and I check what could cause the intrusion after Hitmontop or perhaps a code digit that's typed wrong ever time afterwards, but none of that is the case. All the codes seem to be correct.
Another possibility that can be crossed out is the one of a lack of space. I downloaded the entire (European) cheat database from the Action Replay Database and deleting the cheats for a few of the games I'd never use doesn't seem to help.
Has anyone got a clue how to fix my problem? I'll say once again that I use European Roms and cheats. I live in Belgium, so I only use the American Roms if it's a game not available (yet) in Europe.

(E) roms are not (U) roms. I can tell you that I used a wild modifier cheat as well, and the one I used, you had to use your calculator to input the dex number.http://answers.yahoo.com/question/index?qid=20090324233824AAdsXWBThat is the pre-generated code I used. It worked for me, it's the (U) US ROM, but it also has been verified to work on the (E) roms as well.Remember to follow the directions, as some codes are highly specific.