A couple of possibilities incl;ude the use of wrong drivers:
http://www.microsoft.com/en-us/downl....aspx?id=23734 (though there doesn't appear to be a 64-bit version fo Office 2007). If you need 64-bit support, try the 2010 version:
http://www.microsoft.com/en-us/downl....aspx?id=13255
See also:
http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]