I developed a simple TextBox CustomControl (witin a CustomControl Library project) and added to the AssemblyInfo.vb file the TagPrefix "CustomCntrl". I build the project. On a sample WebForm I add a Tab to my ToolBox and add the dll that houses the TextBox control I developed. When I drag and drop the control onto my form (in design view) then goto HTML view the TagPreix is set to cc1 not the TagPrefix I specified in thr AssemblyInfo.vb file ("CustomCntrl"). Any ideas?