When you're using a Belgian keyboard (or another) on a Windows 2003 Terminal Server, you might have the same problem we had: characters that are formed with a combination of AltGr and other characters (e.g. the @ sign) don't work as they should.
There are two things you can do to work around this problem.
Instead of using AltGr, try using CTRL+ALT and the key you want. This circumvents the problem, but may not be what you want.
You can change the application of Windows key combinations. Rather than applying them to the TS, you can change it so it applies only to the local computer.
This disables the Alt+Tab and Windows key in the TS session, which is probably also not really what you want. On the other hand, it does fix the issue with extended characters.
To change the setting for default RDP sessions, do the following: