Until recently, I've been able to access the secure pages of both my UK banks (Halifax and Nationwide). When I now try to load the pages the sites freeze and I'm unable to progress. The only changes I've made recently to my PC was to install MS Security Essentials and also upgrade to Firefox 4. I've tried lots of things, such as: deleted temporary internet files, installed updated Java, checked that the particular sites aren't blocked, checked SSL settings, uninstalled and reinstalled MS Security Essentials, disabled my Firewall (and turned it back on when discovering this wasn't causing the glitch). I'm at my wits end. Any advice is greatly appreciated.