When I try to do an Update from my Datagrid, I keep getting the old/original values. Why?

This could happen if you are calling .DataBind everytime the Page is loadedTo avoid this call Databind only for the first request and not for subsequent postbacks.

VB.NET

if not Page.IsPostBack then
'Your databinding code
end if

C#

if (!Page.IsPostBack)
{
'Your databinding code
}