Polish months translation

Hi everyone!
I wonder if any native polish speaker or polish expert can help me with this issue.
I have a multi-language website and I have downloaded the .po language file from pl.wordpress.org. for the polish version.
Unfortunately I’ve been told that in polish months are spelled different whether they are in the context of a full date (1st of December 2012 – 1 grudnia 2012) or not (December 2012 – Grudzień 2012).
This is causing me headache since my site has to display both full dates, for instance in the news, and shorter date version, in news archives.

As of now, I have found workaround by hooking into the wp_get_archive filter and replacing the month default name – as set in the .po file – with the correct version for the archive context .

However I was wondering if the polish wordpress community has already found a nicer solution for this problem.

any suggestion is very welcome!