[AccessD] MSACCESS.EXE Still Visible in Windows Task Manager after DoCmd.Quit Command

Occasionally, we notice that an Access 2007 application is still visible
in the Windows Task Manager after the "DoCmd.Quit acQuitSaveNone" is
issued. 
 
(Even after waiting 10 minutes after the DoCmd.Quit command is issued) 

To the user, the Access application has disappeared, but it still is
visible in the Windows Task Manager under the Processes Tab

We can, of course, kill off the application in the Windows Task Manager,
but we would prefer to not do this.

I am curious as to why this is happening.

Is there something that can be done in the Access application to prevent
this?

Have other people seen this happen?

Thanks,
Brad