This kinda pissed me off, and I wrote a blogpost about it. Someone gave me a tip that there are changes that needs to be made in the wp-config.php file.
So I checked the wp-config-sample.php file that was a part of the upgrade. I manually edited my old wp-config.php file to match the sample-file. No luck. The only change I could see was the fact that all the norwegian letters had gone sailing in la-la-land.
So I changed a few more things. Removed spaces between the code that was not there in the old wp-config.php file and I commented out two lines
//define('DB_CHARSET', 'utf8');
//define('DB_COLLATE', '');
Saved the file, emptied my opera cache.. and what do you know, now I can log into my blog via opera again.
What does the 2 lines that I have commented out do? Do I need them? Is there any sane reason why they would mess with the logon in opera?
I'll just leave them like this until I see a reason to put them back in