Move Between Input Cells By Keyboard

There are a series of input cells in a protected worksheet and when the user hits an enter, tab or arrow key, the selection cycles through them in order. The cycle also restarts when the mouse clicks one of the cells out of order. After I switch worksheets and return to the first worksheet with the code, first it says there is a "Compile Error: Sub or Function Not Defined" and the code "Call SetKeys" in Sheet1 is hilighted. When I ignore that and stop the debugger, there is a "Run-time error '13' Type mismatch" and the code line "If arrIndex > 0 And arrIndex < UBound(arr) Then" is highlighted.

My question is: why doesn't the code work after I switch worksheets? especially given that it works perfectly before I switch worksheets. (ie the file opens on sheet 1 and everything is perfect, click sheet 2 tab and back to sheet 1 - nothing works) I also have yet to figure out why it seems to be necessary to post the same code in both ThisWorkbook and Sheet1.

Private Sub Workbook_Open()
'This code allows the user to change the unlocked cells, but protects each worksheet
Dim wSheet As Worksheet
For Each wSheet In Worksheets
wSheet.Protect Password:="mypassword", _
UserInterFaceOnly:=True
Next wSheet............................