Brush, can you describe your settings a bit more?
I just send myself three mailings without a problem, one with header and footer set to '- none ', second after disabling the default header and footer (and, as well, leaving the settings of the mailing with the default ' none -'s), third with the header and footer enabled again and actually selected for this particular mailing and all the mailings was sent properly...
Can I get SSH+CiviMail access to your box (shot@civicrm.org)?
No response received so far; marking as 'Cannot Reproduce' for now.
Make the issue unverified for 1.8.
Reassigning for 1.8 verification.
was not able to replicate this on my local machine. can you give more details about your installation and steps to replicate this.