t I know that they don't really 'like' foreigners
I am a foreigner, i lived in Lodz and now i spend one week per month in Warsaw.
I NEVER felt that people hated me.
Why?
Simple: I Respect polish culture and as the phrase says, "When in Rome, act like the romans". So people even like me. From ALL the countries that i had been, together with Lithuania and Georgia, Poland was were i felt more welcome.
By the way, i live in a muslim/arab country and here most western girls feels really unwelcome (me not, since i am a man) just because they use western clothes. Think about that.