If you’re using Chrome and in StreetView, toggling the left sidebar will turn the StreetView pane solid black. You can’t escape this without refreshing the browser, which takes you back to your default view.
It’s certainly not a huge deal, but it’s one that will affect a good number of users. It apparently happens in all versions Chrome, and I’ve confirmed it in mine (0.4.154.29). Once I hear that it’s been If I hear that it’s been fixed, I’ll post again.