Context Found, but Reactions Not Working

Hello,

I wonder if anyone can help us with this strange problem.

On a fresh install of Context with the latest version of Drupal, I can verify that my contexts are being found using the Context Devel block, but the reactions absolutely will not work. I've tried adding blocks, disabling block regions, and other things, but nothing happens, even if a context is found.

The only strange thing I've noticed in the module is that it lists a bunch of blocks in my block regions that aren't actually there. For example, I am not using my sidebar_left region at all, but it shows a bunch of blocks there in gray text. Could there be a problem with my theme's block configuration? To test, I tried Context with one of Drupal's themes, Minelli, but the same thing happened: context found, but no actions performed.

Any help would be greatly appreciated