unable to connect to cox via internet explorer

I recently began having issues connecting with cox.net webmail and other cox sites using internet explorer.  I can connect through firefox.  I have always used internet explorer as my default browser, and this issue only recently started.  In addition to my McAfee security from Cox, I tried downloading the Cox PC health check, but it says file or directory not found when I try to look at the recommendations after a scan.  Ideas on what the issue may be?