IE6 has Iframes turned off by default, when internet security is set to default level.

 

 

http://72.14.209.104/search?q=cache:Bk7sk3vm8HoJ:www.microsoft.com/windows/ie/using/howto/security/setup.mspx+iframe+disabled+in+ie6&hl=en&gl=us&ct=clnk&cd=1

 

 

go here and Iframe should be highlighted in yellow,  I think you should add this website you want to use in Trusted Sites portion of Internet security, that way you do not open up your browser to vulnerabilities  that other websites amy take advantage of.

 

You can find these security settings in Tools/internet options/security tab. Do some reading first.