Polish to English subtitles also have problems, not in content so much as style.
I believe that when Kieslowski worked on Three Colours White, he was very careful with the translations. Maybe working with both French and Polish meant that his later films had a more international audience and therefore had to be well presented to international audiences. Also, he was a great film-maker with a good level of control over what he could produce. Many other film-makers are either not looking towards so much of a market outside of Poland or at least have less control over the finished product.
I am downloading Polish movies or English ones with Polish subtitles I really find it helpful for picking up some verbs and picking up on word order.
I think I've only seen one film in English with Polish subtitles amongst the many I have been sat in front of (usually with copious amounts of food, alcohol and large families often with children or dogs). It made a nice change to be able to actually take in all of the film with odd little Polish lessons at the bottom of the screen. Z tym filmem, pamiętam że uczy się "pamiętam". Obviously I still have a long way to go remembering everything I learn.
I notice the old lektor chap doesn't always like all the swearing in English dialogue.