Setting up YaBB Perl forum - weird respond as plain text in browser, including headers

Hi everyone,

I'm a real beginner to perl, and tried to start messing around with
YaBB forum. It all went smooth on one server, but when I've tried to
install the forum on another one and run Setup.pl, I get a plain text
in my browser including header. Here is the respond I get in my
browser:

Status: 200 OK
Cache-Control: no-cache, must-revalidate
Pragma: no-cache
Content-Type: text/html


"http://
www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">