mp3blaster does not paint borders. For making it painting them is necessary to change main.cc, adding an include (#include <locale.h>), and then, the first line of int main() can be "setlocale(LC_ALL, "");", this way mp3blaster will be shown as expected.
Created attachment 96268 [details, diff] Patch for mp3blaster
This can be reproducible by using a system-wide UTF-8 system, with 02locale as follows: LC_ALL="es_ES.UTF-8" LANGUAGE="es_ES.UTF-8" LANG="es_ES.UTF-8" Here there is no X installed, so mp3blaster is running in console (ttyX). Lines won't be drawn if USE="unicode" was marked when ncurses were emerged (compiled). Sorry for the first lack of information.
(In reply to comment #1) > Created an attachment (id=96268) [edit] > Patch for mp3blaster > What happens to filenames with UTF-8 chars in them with this patch?
Looks and works fine here with fi_FI.utf8. Your consolefont is likely wrong.