Word Document Printing Issue

I am trying to print a Word 2003 document in my program by using an Interop object downaloded from Microsoft. (Interop.Word.dll). Below lists part of my code.

Public ObjWordBasic As Object
Public WordApp As Word.Application

My_Word.WordApp = CreateObject("word.application")
My_Word.WordApp.Documents.Open(WordFilePath & WordFileName)

My_Word.ObjWordBasic = CreateObject("Word.Basic")
If My_Word.ObjWordBasic IsNot Nothing Then
        My_Word.ObjWordBasic.fileprint(0)
End If
.........
If My_Word.ObjWordBasic IsNot Nothing Then
                My_Word.ObjWordBasic.fileexit(2)
                My_Word = Nothing
End If

Somehow, oscasionally, I found that there is a WinWord.exe process left when checking the WIndows Task Manager after the printing. This causes the printing of another document failed.
I need to manually kill the WinWord.exe process left to resume the printing.

Please advise how I can rectify this problem. Thanks.