When you use this
VB Code:
  1. Private Sub Combo1_Click()
  2.       frmMain.txtxtext2(i).Text = Combo1.Text
  3. End Sub
Your program does not know what i equals so it doesn't know what textbox to put it in. When you declare a number variable, it defaults to 0, which is why your text is going into to Text1(0).Text. The question you have to answer is:
VB Code:
  1. 'do you want the text in
  2.       frmMain.txtxtext2(0).Text = Combo1.Text
  3.       'or do you want the text in
  4.       frmMain.txtxtext2(1).Text = Combo1.Text
  5.      'or do you want the text in
  6.       frmMain.txtxtext2(2).Text = Combo1.Text
  7.      'or do you want the text in
  8.       frmMain.txtxtext2(3).Text = Combo1.Text
  9.      'or do you want the text in
  10.       frmMain.txtxtext2(4).Text = Combo1.Text
Whichever is the case, replace i with the textboxs array number.

PS: I have added [vbcode][/vbcode] tags to your last post. As you can see, it makes reading what has been posted a lot easier.