At the URL "https://es.infragistics.com/Membership/Default.aspx?panel=Downloads#HelpCenter" there is a WebTab control with two tabs "Support Requests" and "Bug Tracking."
As of today, this WebTab control is non-functional with Internet Explorer 7. It's working fine with Firefox 3.
Thanks for mentioning this.
I've taken a look at this page through Internet Explorer 7 (specifically version 7.0.6001.18000), and it came up correctly. I'm able to switch tabs successfully.
Take a look in the bottom left-hand corner of your browser window. Do you see an error icon there (a yellow shield with a black exclamation point)? If so, a JavaScript error probably occurred, which would cause the tab to stop functioning.