Run & ShellExecute Behavior Help

Simply put, I have a "mother" program that runs other .exe's ... "children" ...  in a sub folder based on what a user checks on a GUI provided.

Using the following code from the "Mother", I get an @Error that one of the "children" return... telling me the excel file it is trying to Open could not be found. (Note: The "mother" program does not have any errors. I error check like I breath oxygen...)

However... If I run the child myself, it runs without any problem. Any ideas?

While 1
   $nMsg = GUIGetMsg()
   Switch $nMsg
      Case $GUI_EVENT_CLOSE
         Exit
      Case $oChild
         If GUICtrlRead($AZ) = $GUI_CHECKED Then
            $site = "AZ"
            Run(@ScriptDir & "\Site_Specific\"&$site&"\"&$site&".exe")
         EndIf
   EndSwitch
WEnd

EDIT: I love how my topic title is about behavioral problems... And my post is about "mothers" and "children".

EDIT2: I have quadruple checked to make sure paths were defined correctly. I have also tried running the child through scite as an au3... making sure it works properly... and then recompiling. No issues. Mother runs it? Not happening.