I am really hoping I've missed something obvious and somebody here can go "oh it's THAT, fool"....

I've used Spybot for years and never had a problem at all. Today I put the newest free version for home users on my Windows 7-running laptop. I ran a scan, it seemed fine (the only things put up for deletion were cookies - all listed Level 5). Except that as soon as I'd done that, my internet browser - I use the latest version of Opera - suddenly went weird, requiring me to authorise every website I go to and not showing me pictures. One journal site I go to won't load the individual post pages in anything approaching a sensible manner and won't show comments. It looks like it must have done something to the 'security' settings, but nothing I can see or change in Opera seems to be helping. It's really weird. Any suggestions?