This situation is not dangerous, not urgent 😀 …
<following article was made with machine translation.>
about a detailed content(Japanese): Opera integrate thread 91th(dies soon)
Influences: Opera 9.0-9.27 higher (9.5 beta corresponds, too.)
Tools -> Preferences -> Advanced -> Shortcuts -> Middle click options
Select "Open in new tab".
Please open suitable page where iframe is included.
Click hyperlink in iframe with middle button.
Shuts an new tab.
Mouse operation freezes except iframe.
ALL YOUR OPERA ARE BELONG TO US.:faint: