Since the Hide() / Show() methods are not functional in C#2.x , we have to find a work arround.
Simple workarround:
/* In the Form_Load() method hide the tab ( if you wish to initialy hide the tab) assuming the name of the tab page is TP */
tabControl1.TabPages.Remove(TP);
/* if you want to show the tab page add to the end */
tabControl1.TabPages.Add(TP);
or
/* if you want it to always be the second tab for example */
tabControl1.TabPages.Insert(1,TP);
Have fun Tabbing!