[Zope] 2.4.1 install problem

Howdy! I'm trying to install 2.4.1 (from source) on OpenBSD 2.9. When it comes to make in the ISO_8859_1_Splitter folder make stops with 'don't know how to make ././src/ISO_8859_1_Splitter.c'. That's no wonder, because the latter file is not in there. Only when I rename the file ISO_885 in the src directory to ISO_8859_1_Splitter.c everything works. But is it meant to be like that? What's going on? Ragnar