Thank you for writing.
In this case you should set a location for the controls, this is needed because as you can see their default location is (0,0) and they are positioned at the top left corner of the group box. For example you can initialize the controls as follows:
textbox.Width = 100
Please let me know if there is something else I can help you with.
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos
and start improving your app based on facts, not hunches.