title: User control doesn't react when I pressed a tab button
body: <p>I have a windows application: a main form and several user controls on it.</p>
  
  <p>Tab button doesn't work as I expected. I thought it goes through all user controls on form. But I was wrong. When user control received focus (using mouse click) it didn't want to go anyway using tab button. What thing can be wrong ? Did I miss something ?</p>
  
  <p>I didn't override ProcessCmdKey and other key_down events. All user controls have TabStop property = true.</p>
  
  <p>C#, .net 2.0, WinForms</p>