Custom Translate.csv File Not Loading in Magento 1.9

I'm still not 100% sure what you're asking, but looking at your code

<reference name="header">

    <!-- Quick Cart Dropdown -->
        <block type="checkout/cart_sidebar" name="minicart" template="checkout/cart/header.phtml">
    <action method="addItemRender"><type>simple</type><block>checkout/cart_item_renderer</block><template>checkout/cart/sidebar/default.phtml</template></action>
        <action method="addItemRender"><type>grouped</type><block>checkout/cart_item_renderer_grouped</block><template>checkout/cart/sidebar/default.phtml</template></action>
        <action method="addItemRender"><type>configurable</type><block>checkout/cart_item_renderer_configurable</block><template>checkout/cart/sidebar/default.phtml</template></action>
    </block>

    </reference>

Here you're adding a new block named minicart to the header block. However, the header block is a template block, which means it does not automatically render blocks that have been added to it. You'd need to have a

$this->getChildHtml('minicart');

In your

page/html/header.phtml

template.

I found this old topic, and later found a solution: when the same string exists in multiple module translation files, then Magento will scope it, by default with '::'. So you also have to create separate translation strings for all those scopes in your translation.csv

"Mage_Customer::Fax","Fax"
"Mage_Checkout::Fax","Fax"

And for all the other modules in which "Fax" appears (and you care to translate differently).