https://bugs.winehq.org/show_bug.cgi?id=40787
--- Comment #1 from Ladislav Láska ladislav.laska@gmail.com --- More digging revealed, that this is in fact a regression. I did some rough testing with PlayOnLinux, as I'm unable to compile wine-1.1.x on my current system.
The POI Loader seems to be working with 1.0.0 and 1.1.0 (though the installer is broken). Tested with versions 2.7.3 and 2.5.3.
The first broken version I know of is 1.1.29. I will try to bisect it later, if I manage to compile the older versions.