I export versions from Aperture then drag the jpeg images to an email which is sent. I open the email on a Windows machine and try to open the image files but get the message "No preview available" from Windows Picture and Fax Viewer or Microsoft Office Picture Manager. So I'm unable to email tese images to people who have Windows machines. Usually when I export masters this problem does not occur. I tried importing my exported images and then re-exporting as masters but this did not fix the problem. Anyone know what is going on?