I dare to disagree. :)
You're right, Rubaszny and I was wrong. It's "zdanie wtrącone" in polish grammar and a comma has its right place here. Being native Pole still demends me to learn the language. I here stand corrected. Thank You.
Still the two examples i provided are correct grammar-wise. Or not? I have doubts about the "one sentence" one.
Thanks for clarifying, Jon.