On renewal, I need to generate a PFX file in addition to binding to IIS. Using the latest 2.2 version, I've set this up and it is running correctly except that it seems to be appending the new cert to the PFX file rather than overwriting the cert. This is the command line that it is running:
wacs.exe --source iis --commonname mail1.MYDOMAIN.net --siteid 2 --store certificatestore,pfxfile --pfxfilepath c:\SmarterMail\Certificates\ --installation iis

Is there something I should be doing differently? If I delete the pfx file and then run the renewal, everything is great.