Thanks, Wilkolak, for this info. So many times in my life people have asked me if I was Polish – even people from Poland ask if I'm from there!
Also my uncle who was born in Croatia told me he heard tales that our family ancestors came from Poland many ages ago.

It's a pleasure. Pentaz also started this interesting thread on White Croats (if you haven't seen it before): http://www.slavorum.com/index.php?topic=152.0

There is great chance I have much White Croat origins as well, since according to this map (which corresponds to old White Croatia that was later Polonized by Bolesław Chrobry):


My paternal Grandfather's family originates close to Rzeszów and both my paternal Grandmother's family and entire maternal line originate from around Radom, which now lies in Masowsze voivodship, but historically was found in Kielce voivodship of old, which was part of historical Małopolska region, which basically in historical entirety was White Croatia.

Since essentially my entire family (and not only my paternal Grandafather's line, as I previously thought) originates from historical Małopolska, I probably share some common lines with modern Croats as well.

This is also probably why some people confuse you with Poles also. ;) Common roots.