Clicking 'Open in new tab' opens in new window

Since the latest update (8.01), I've been unable to open links in new tabs without dragging the link up to the tab bar. Alt-clicking the link and clicking 'open in new tab' opens the link in a new window instead (The 'open in new window' works as it should). Also, middle button clicking opens in new window, even though I have the 'Open new windows in a new tab instead' selected in the tabs option menu.