Jason,
I installed the .xml file as instructed with Dreamweaver closed. I deleted the .dat file as well. Same problem. If I make changes to the Server Behavior then re-upload, the emails come back as pure text files every time.
However, if I manually change then re-upload the mail_PHP.php (changing $lineEnd = "\r\n"; as instructed) file AFTER changing the server behavior, it works perfectly.
That's what I would call a bug.
I'm on CS3 on Mac OS 10.5.8