Excel 2000 SP3

I have an add-in I wrote, (One of many) myaddin.xla
For a simple breakdown, The add-in opens excel files, updates them via ADO
2.7. Closes and saves the files.

The add-in is called from an application called AutoMate. Using the
following code.
Private Sub Main
Dim xlApp As New Excel.Application
xlApp.Workbooks.Open "C:\myaddin.xla"
xlApp.Visible = True
xlApp.Run "MyModuleName"
xlApp.Quit
Set xlApp = Nothing
End Sub

This add-in updates 200+ workbooks. The problem I am having is that it is
running out of memory about half way through.
I am seeing something strange that may be someone else has seen and can give
me some advise on.

After the add-in opens, updates and closes the workbook. The workbook is
still listed in the VBAProject window. Still in memory.
It is closing the Excel Workbooks but not destroying them. I am using the
following syntax.

xlApp.ActiveWorkbook.Close SaveChanges:= True

Thank you in advance for any thoughts and or help.
Kent Prokopy