Not translatable strings

edit

I can translate most of the strings in django.po

but some strings appear in english although they are tranlated in django.po

for example this one in ru locale:

#: forms.py:932
msgid "Screen name"
msgstr "Отображаемое имя"

i've compiled with:

python ../manage.py compilemessages

I have this problem with some strings not with all. And these strings don't differ from the working strings.

Why? And how to solve this? Thanks

Edit: No idea?