I was wondering the same, but i did not start yet asking for the taxes, as i do think that as my income is from outside, then no need to pay here.
You need to pay. Poland's tax residency law states that if you spend more than 185 days a year in Poland, then you are resident in Poland for tax purposes. As you've got the residency permit - then this is more or less a formal declaration that you are in fact resident.
Taxation for you will be 19% of dividends, plus whatever taxation is due on your salary (which is quite substantial - if you pay yourself around 6000 pounds a year, you'll have quite a big Polish tax bill - 19% Polish income tax, plus around 40% of gross salary in social taxation as an employer and employee).