hello everyone. i have a vb.net application that was working fine, but now it is bombing. I am using the excel 9.0 object library

Public ExcelApp As Excel.Application
ExcelApp = CreateObject("Excel.Application")
' the application bombs on the above line with the error specified cast is invalid.
' i have also tried the code statements below and although the application
' doesn't blow up right away, you can tell the excelapp object is not set
' properly because none of its properties or methods are accessible.

ExcelApp = CType(CreateObject("Excel.Application"), Excel.Application)
ExcelApp = DirectCast(CreateObject("Excel.Application"), Excel.Application)
ExcelApp = New Excel.Application

Any ideas. As far as the machine it runs on office has been updated from 2000 to 2003; however this is bombing on my machine as well and i have not upgraded.

thanks for the help.