> I am not sure about the part you mention of reloading the original control and then the new one. If I reload the original control, I would then have to get rid of it before I load the new one; I don't want both.

Yes, that's correct. The weird part is that you even have to do it at all. What's the point of reloading a control only to immediately remove it? But you do.

>I am not sure why the PreRender didn't work then. All my basic controls; textbox and such were null when the PreRender fired.

All of the controls on the page or controls in your user control? On both Init and Postback?