I'm having a performance problem on my company's web site using a specific version of IE 8 to load a page using https. Here's what I know.

Server: Virtual machine running on VMWare ESX Windows Server 2003 Enterprise Edition SP 2 Tomcat 6.0.16

Client: Windows XP and Window 7 Internet Explorer 8.0.7600.16385IC

Page loads/refreshes in under 1 second using HTTP. Page loads/refreshes in 15-16 seconds in HTTPS using this version of IE. Problem reproduced on multiple client machines with same IE version. Problem reproduced on multiple client machines with different Windows versions (XP and 7). No performance problem using Chrome, Firefox, Opera, or Safari from same machine. No performance problem using other versions of IE 8 on other machines. Slow load causes virtually no CPU, memory, or I/O spike on server or client machine. No performance problem on other sites using HTTPS on same client machine.

The pages in question use JavaScript and innerHTML to replace the contents of div elements to create a collapsible menu, and an iframe to display some content. A couple of the div elements contain images. If I remove the iframe and the JavaScript, the performance issues go away. However, rewriting the entire site to make these changes would be very time consuming. We're in the process of replacing the whole site, but it may be 2-3 months before we do so and we really cannot live with this slowdown that long. I've already looked at several IE tuning options, such as disabling add ons, running IE-rereg, and resetting IE, with no luck.

Does anyone have any suggestions?