Doesn't support ActiveX controls on Macintosh. Doesn't support the Spacer tag. Use a small transparent gif instead or the CyberStudio Layout Grid. Support for click sounds and background sounds is different than in Netscape. Use a Java Applet or a Plug-in such as QuickTime or Flash.
Tables sometimes appear differently than in Netscape.
Container Everything in CyberStudio. A Layout Grid can't consistently be centered on the page. Can be fixed by adding a small empty text box below the last graphic. Windows versions can't handle negative numbers in imagemaps. Internet Explorer 3 on Windows can't do email from a form.