What antivirus do you use? The last beta-version has similar problem when Avast antivirus is used.yes it does
every other tab i open as well as trying to open numerous tabs at once almost always results in this error. this is in the 64bit version of opera by the way.
New beta-version is out soon (today or on monday), try to reproduce this problem please.further observations indicate that this problem seems to get worse when there are bandwidth intensive operations going on so if i'm downloading a file it will get worse. hope this helps.