Remove SaveAs prompt for Word 2007 VBA SaveAs in 64-bit Window 2008

Question

We use VBA WordApp_DocumentBeforeClose(ByVal Doc As Document, Cancel As Boolean)
to save the word file to another name when user closes the file  .
We use SaveAs to implement this like this:
 Doc.SaveAs FileName:=lcMetaFileName,  AddToRecentFiles:=False
The lcMetaFileName is a file ame with full path.
This SaveAs works fine with word 2003 and with word 2007 in Wndow 2008 32-bit.
But with word 2007 in Wndow 2008 64-bit,every time this SaveAs is called ,
a saveas prompt will be showed up asking for file ame , type,etc.
We tried  adding 
   fileFormat:=wdFormatDocument97
in the SaveAs call and adding
Doc.Application.DisplayAlerts=wdAlertsNone
and checked 'allow back ground save' in the word setting
and we still get the prompt.
How can we get rid of the prompt?

Answer 1

Same here. My program uses demographics to create a filename and filetye as RTF, but it is ignored and a prompt pops up !!!! Frustating :(
OS - Win 8.1 64 bit
Office 365 32 bit (Word 2013)
Same code works for all other versions