I've just spent hours selecting and then bookmarking seven pages off a website and filed them neatly in the correct bookmarks folder for later perusal.

Now, and I've never seen this before, when I click on those bookmarks, they each open in the sidebar, leaving Google my home page, open in the main browser window.

This is very irritating. I've had to go to Manage Bookmarks, control+click on them one by one and say "Open in new window". This then opens seven new windows. The original bookmarks still open in the sidebar. WHY? Why only those bookmarks and no others? How can I make the blasted things open in the main window just like every other bookmark I've ever made in my life?

Thanks. I'm sure there's a simple explanation and fix, but I've just wasted another couple of hours on a research project.