I found two conflicting arguments for this on Microsoft's very own website: "Internet Explorer 3.0...PNG graphics"http://support.microsoft.com/kb/825461 and "PNG output format requires Internet Explorer 4.0 or later"http://office.microsoft.com/en-us/visio/HP010501811033.aspx, yet there is no mention of PNG in the Internet_Explorer_3 article. I'm not sure what to believe. Time to install Multiple IE.http://tredosoft.com/Multiple_IE