Sometimes you fix a bug and by doing this, you create 3 others without noticing it. This is more or less what happened with Polylang 1.4.4. These bugs (which lead to unexpected redirections in some cases) were quickly fixed in the development version as soon as they were reported. And hopefully Polylang 1.4.5 will be more stable than the previous version. I am sorry for the inconvenience.
Polylang 1.4.5 also fixes a bug appeared with WordPress 3.9 (uploaded media don’t get a language) that I did not notice while doing my tests with beta versions of WordPress.
I added compatibility with the Twenty Fourteen Ephemera widget which has been modified in the version shipped with WordPress 3.9. Please make sure to have the latest Twenty Fourteen translations. If you get untranslated strings in this widget on frontend, check the theme translations with a plugin like Codestyling localization. The next major version will drop the compatibility with the Twenty Fourteen Ephemera widget shipped with WordPress 3.8.
Finally, I also fixed a notice displayed by WordPress SEO when Polylang is combined with WordPress SEO 1.5+. It’s likely that starting from the next major version, I will support only WordPress SEO 1.5+.