Hi Jedf,
Thank you for writing.
A possible reason for the missing control in the Toolbox is if your project's Target Framework refers to a Client Profile of the .NET Framework. Please change it to a full profile in order to show it in the toolbox. See attached image.
I hope that you find this information useful. Should you have any other questions, do not hesitate to contact us.
Kind regards
Stefan
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.