Urgent: Polish fonts in Win32

["Bartosz \"Neron\" Leper" <bl_nero o2 pl>]

I'm a newbie here. Please help me - it's very important.

I'm Polish and I've written an application on Linux using Gtk. Then I've
compiled it under Win32. It turned out, that everything was good, except ALL
the strings containing Polish letters. Every label containing such text was
just gone (those including only English alphabet were still there), but the
text entries were OK.

What's wrong?

Bartosz Leper