Paweł Pyrczak, oh, the TazPanel has seen some metamorphosis. In particular, the page "Packages" moved to TazPkg. I updated translation files so that they are consistent with the current Panel code.
Please recheck the translation and translate the untranslated strings: http://hg.slitaz.org/tazpanel/raw-file/d1f4f991fb1d/po/pl.po About untranslated buttons, thanks for the idea, I will test it tomorrow.

