I'm getting used to Opera (7.51) but there's one thing I haven't figured out yet.
When adding an item to my shopping cart, the cart will return me to the page I started from. Opera always returns me to my index page, not to the page where I started from. I've looked, and can't find a setting in Opera to 'fix' this, and it's the only browser that I know of that behaves like this.
Fortunately, the really really nice navigation abilities make this easy to overcome, I just right click-left click to get back to my page. But it's bothersome, and I know one of these days one of my customers is going to ask me about this.