In Opera, when a link opens a new tab or window, and also triggers a download dialogue, a blank page is opened first, and then left behind after the dialogue is completed or cancelled. This isn't a serious flaw, but it is an annoyance, to be sure. Opera should close new tabs or windows automatically if they trigger a download dialogue, since no displayable content is available.
For comparison, in their default setups, Firefox will leave the tab or window open as Opera does, while Internet Explorer will close it.
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