We currently having an issue with IE 11 on systems that upgrade from a IEAK configured IE 8 browser.
If a user upgrades IE 8 to IE 11 and installs the IE 11 cumulative security update KB295418 (win7X64) the user can no longer travel from a HTTPS to HTTPS page, or from HTTPS to HTTP page. If you uncheck the advance setting: Warn if changing between secure & unsecure pages it fixes the issue. It appears that the KB breaks the dialog box that comes up to warn you that you are going to a secure or unsecure page. This dialog box does not appear if you have the KB installed. If the KB is not installed there are no issues, dialog box appears and everything works as it should.