Visual Studio .NET 2003's Windows Forms designer can do better than world's best magicians - it can make controls disappear from a form without any apparent reason. Anyone expecting it not to turn the development process to a magic show should read these KB articles:
http://support.microsoft.com/kb/842706/en-us
http://support.microsoft.com/kb/818220/en-us
http://support.microsoft.com/kb/911952/en-us
http://support.microsoft.com/kb/322730/en-us