This usually happens to me. I have a repeater object, do a "FindControl" to look for a textbox, and can't find it. Ends up null each time.

So, tired of finding complex workarounds...I finally researched this issue.

Here's the solution:
 

Code:

foreach(RepeaterItem item in Repeater1.Items)    {       TextBox b = item.FindControl("TextBox1") as TextBox;       Response.Write(b.Text + "<br>");                          }

Ahhh....makes much sense  

Must love the internet

Source: http://www.odetocode.com/articles/116.aspx