Panel with a Visible property that won't update

What's wrong with this pseudo-code?

Panel p = gridItems.Rows[0].FindControl("pnlHiddenByDefault");
//do some other random stuff
gridItems.DataBind();
//do more random stuff
p.Visible = true; //FAIL

The code will execute fine but even after setting the Visible property to true, a QuickWatch will show the property is still false.

The fix:

Panel p = gridItems.Rows[0].FindControl("pnlHiddenByDefault");
//do some other random stuff
gridItems.DataBind();
//do more random stuff
//get fresh reference after DataBind
p = gridItems.Rows[0].FindControl("pnlHiddenByDefault");

p.Visible = true; //WIN