Ya, ur going about it just a little wrong.

Instead of doing:

Label l = (Label)e.Item.FindControls("someId");
if (l.Text == "0")
{
 //hide
}

use the e.Item.DataItem property which gives you access the the underlying
data being bound.  So if you are binding to a dataset/dataview/datatable,
you would do:

int id = Convert.ToInt32(((DataRowView)e.Item.DataItem)["SomeId"]);
if (id == 0)
{
 e.Item.FindControls("link").Visible = false;
}

Karl

In addition to Karl's answer, there is another way. You can build the entire
"data grid" from scratch in code behind. I would only go this route, however,
if it is absolutely necessary, as it is a pain.