Same problem here.
Not with Types plugin but WP Simple Paypal Shopping Cart. Language plugin never switch, it keeps using the selected default language and the translation given by plugin's .mo files.
After spent a few hours digging on this the conclusion seems to be same: Polylang gets in action too late.
I got into that idea after read this:
http://geertdedeckere.be/article/loading-wordpress-language-files-the-right-way
