for this problem, now i’ve found the solution.
1. disable all plugins, except akismet.
2. download wordpress.zip from www.remarpro.com and extract.
3. from step 2, upload folder theme /twentytwelve to your website (i use filezilla). you only need this theme in original version.
4. download your wp-config.php
5. from step 2, upload everything to your wordpress installation (via ftp filezilla).
6. now, login to your dashboard.
7. this is important: choose “twenty twelve” theme. dont worry,, your custom theme and any settings will not gone.
8. click update wordpress 3.5, just klik update.
9. now,, enable all your plugin from step 1.
i prove it. you dont need 10 minutes to do these steps. good luck.
i am indonesian, a webmaster from https://mataairradio.net *) it’s streaming now!