[Zope] Mac/IE Image Uploads

Just noticed that when I upload images through Internet Explorer with my Mac they don't get the right file type and they don't work even once I change the file type. Netscape works fine. Is there a workaround for this (which is probably an IE problem more than ZOPE). BTW we're about ready to start ZOPE hosting so if you want to contact me off-list please do! Josh