Thank you, I tried to check some other sites, but it unfortunately happens only to me
--------------- Added [DATE]1284891929[/DATE] at [TIME]1284891929[/TIME] ---------------
I found out!!!
It's a codification problem. I get that error if I save the php file in UTF-8. But is should be saved in ANSI.
However if I use ANSI I cannot use the special characters ł?ężźć, but I need them.
I have to use online converters from whatever to ANSI :/
BTW, thanks much for your support