Thanks for adding me to the nosy list.  Yep, this code is pretty old so it doesn't surprise me that its implementation isn't quite right.  Of course, I hate get_payload(decode=True) anyway and hope that goes away in email 6.

Having said that, I don't think this can be changed in Python 2.6.  It's pretty common for people to have workarounds for the devil they know and I'd bet that changing this behavior in 2.6.x would break people's code.  I'm okay for doing the sensible thing in Python 2.7 (though we should probably bump the email package's micro version).