Model->Save() Duplication Issue

Hi

I've created an import function in my module which is triggered by an action.
The database is SQLite

The flow are as follows

Action: InitializeModule
This action has no form and will redirect to another action after completing the initialization of the module.
public function actionInitialize()
{
$module = $this->module;

$module->initializeModule();

//$this->redirect(array('index'));
}

InitializeModule method:
The method checks if a field is set in my parameter table. If not set it will create a record and start importing data from files located in a folder located within the module structure.
Each file is read line by line, i.e "sfi18n";"ISO";"en";"ISO"
The first field (sfi18n) identifies the unique key in my category table.

For each line, I check if the category exists and if it doesn't I create it.
The code are as follows:

public static function findOrCreateCategory($categoryName)
{
// Search for categry
$category = Category::model()->findByAttributes(array('CategoryId' => $categoryName));

if (!isset($category->CategoryId))
{
$category = new Category();

$category->CategoryId = $categoryName;
$category->Name = $categoryName;

$category->save();
}

return $category;
}

For some reason the two first times it enters this method it will create a record. The rest of the times it finds the category and ignores the insert.

The result in my table is to identical records (even though I have CategoryId as uniqe key and and unique index on the field)

I've also tried creating an SQL command but it made no differnce.

Does anyone know where I should start looking?