Attempting to filter by first letter of product names but will only filter products on current page

[tmillsmonin]

My module is working on a fresh install of Magento CE 1.9 but not on my existing EE website. Here is the module on GIT. 

Using the configuration below, I am able to modify my collection, but it only applies to the results on the current pagination page. So, if I am on page one and I have a product starting with the letter A and modify the collection with ->addAttributeToFilter("name",["like"=>"a%"]) I see only the products that start with the letter a for the current page. If I am on page one and modify the collection with ->addAttributeToFilter("name",["like"=>"m%"]) I do not see products beginning with the letter M, I get Magento's "no products found" message. If I go to the pagination page that contains products with the letter M and use ->addAttributeToFilter("name",["like"=>"m%"]) I see only products starting with M that were on the current page.

How do I filter by letter prior to pagination and any other filters being applied?

config.xml

        <catalog_product_collection_apply_limitations_after>
            <observers>
                <etre_alphapagination>
                    <type>model</type>
                    <class>etre_alphapagination/observer</class>
                    <method>applyFilter</method>
                </etre_alphapagination>
            </observers>
        </catalog_product_collection_apply_limitations_after>

Observer.php

public function applyFilter($observer)
{

    if ($alphaFilter = Mage::getModel('etre_alphapagination/parametersactions')->currentAlphaFilter()) {
        $event = $observer->getEvent();
        $collection = Mage::getModel('etre_alphapagination/parametersactions')->applyFilter($event->getCollection(), $alphaFilter, "name");
        return $this;
    }
}

Mage::getModel('etre_alphapagination/parametersactions')->applyFilter($event->getCollection(), $alphaFilter, "name") refers to:

public function applyFilter($collection, $query = "", $attribute = 'name') //let's provide the option to filter the collection by whichever attribute desired
{
    try {
        $collection->addAttributeToFilter('name', array('like' => $query . '%'));
    } catch (Exception $e) {
        Mage::logException($e);
    }
    return $collection;
}

If I execute the code below, I get zero results on my filter.

public function getLoadedProductCollection()
{
    die(zend_debug::dump($this->_getProductCollection()->getData()));
    return $this->_getProductCollection();
}

If I execute the code bellow from anywhere within  $this->_getProductCollection() I see my expected results.

die(zend_debug::dump($this->_productCollection->getData()));