Hey thanks for pointing that out BC! I thought they were just blank e-mails.
I suspect it has to do with the fact that they are spoofing the recipient. (making the sender impersonate the recipient). I'll bet google doesn't like that. I'm gonna post on the google help groups to see if I get a better answer.
Anyway here is a quick workaround: scroll to the bottom and where is says "google views" click on "basic html", then display the message and click on "show original".
If I find out more, i'll post it, or maybe even forward it to res.net tech support.
_________________________
Rocky