Dashboard not displaying properly after 3.9.1 upgrade

After the automatic upgrade to 3.9.1 my dashboard was not displaying properly, as have been reported by several users. The style for the dashboard seemed broken and several links were not working or giving unexpected answers. Front end of the site was working ok.

I applied every single solution suggested in this thread by Esmi but none of them worked (full plugins disabled, switched to default theme, resetting plugins folder, re-uploading files from fresh WP 3.9.1 download).

I also applied both solutions suggested in this post about a similar problem, but none worked.

I downgraded to 3.9, with no results at all.

The only thing that actually worked was DOWNGRADING to version 3.8.3, which is a big bummer as long as I always try to keep my sites up to date for the obvious reasons.

It seems to me this is obviously related to the 3.9 and 3.9.1 versions and not related to my server’s configuration (Apache 2.2.17, MySQL 5.5.37-cll, PHP 5.2.17).

Anyone with any idea so tons of users having this issue may have a solution?

BTW, this same issue and this same workaround was used to fix up to 6 WP installations I have on my server, all using different themes and plugins, none of them “reacting” to any of the suggested solutions.

Thanks in advance.