In 4D 2004 (as well as previous versions) the Enter key, also called the Keypad Enter, and not to be confused with the Return key, is used as a keyboard shortcut in User/Custom Menus mode to perform an "Accept". This can have unintended side effects if your database does not take this into account. There are at least two ways to deal with this:
-Add an invisible button to the form and set the "Shortcut" for the button to Enter. This way you can capture the Enter keystroke and handle it as needed. Note that you would need to do this for every form.
-In the database Preferences, Application page, Shortcuts section you can disable or change this shortcut to something else for the entire database. Note that there are two other editable keyboard shortcuts on in this section of the Preferences.