This issue is very common since last couple versions. I found this useful article how to resolve it here in version 1.5. and I recommend to read it if you want to understand how quick search works.
Here is my update for version 1.6. Basically same idea with small changes:
Copy: app/code/core/Mage/CatalogSearch/Block/Result.php to: app/code/local/Mage/CatalogSearch/Block/Result.php and uncomment lines 149 and 150: $this->getListBlock() ->setCollection($this->_getProductCollection());
Then go to line 172 and change from: $this->_productCollection = $this->getListBlock()->getLoadedProductCollection();
to: $this->_productCollection = Mage::getSingleton(‘catalogsearch/layer’)->getProductCollection();
Copy: app/code/core/Mage/CatalogSearch/Model/Resource/Fulltext.php to: app/code/local/Mage/CatalogSearch/Model/Resource/Fulltext.php and go to line 356 and change: $likeCond = ‘(‘ . join(‘ OR ‘, $like) . ‘)';
to: $likeCond = ‘(‘ . join(‘ AND ‘, $like) . ‘)';
In Admin Panel -> System -> Configuration -> Catalog -> Catalog Search set Search Type property to “Like”. Then reindex data, refresh cache…