Did you try to comment all these IME lines and don't use the IME stuff:
'IME.Initialize("IME")
' IME.AddHeightChangedEvent
'Sub IME_HeightChanged(NewHeight As Int, OldHeight As Int)
'EditText1.Top = (NewHeight) - EditText1.Height
'End Sub
'Also comment he line in the manifest
In other words, do not use any of the IME stuff and see what happens. If that does not work for you, perhaps you can strip a small project and uploaded it. Somebody may lend you a hand. I have a tabstrip with an editetxt at the bottom of it and when I start typing in the editetxt, it rises. I am not using any of the IME height changed code. I don't know if we have similar cases.