Hi there,
Just had a quick look at your code and noted that it looks like you are opening the destination workbook 'destwb' before the part where you only want the code to fire if it gets passed a "UT-E" value.
everything before this line:
If xCell.Value = "UT-E" Then
Will fire everytime you put any character into the cell, in your code this includes opening the destination file. When you open a file it will switch to it as the new focus window.
Maybe you can move where the destwb is opened in the code or open this file with a seperate sub outside of the change event?
Hope this helps