Does your .po file contain the word "fuzzy"? If so, you might want to read the following article: http://blog.e-shell.org/124, as mentioned in this previous SO question: Django missing translation of some strings. Any idea why?
If that is not the cause of your issue, are you sure you are using the internationalisation template tags appropriately?
First of all, ensure you are loading the relevant template tags at the top of each of your templates:
{% load i18n %}
Then, for any text you want to make translatable:
{% trans "Insert your text here" %}
See also: https://docs.djangoproject.com/en/dev/topics/i18n/translation/#internationalization-in-template-code and https://docs.djangoproject.com/en/dev/topics/i18n/translation/#implementation-notes.