Oh sorry! I compiled the control into a dll, added a reference to it under references in the solution explorer, then added it to the toolbox and dragged it to the webform. Any ideas?
Try removing it from the references and just use it from the Tools. I've created custom control and just use them from the Tools.
It seems that .NET automatically adds a reference to your project at compile time and by having you add it it's causing some conflict.
