New table column not updating in Magento

So you've included a custom section for a table, e.g. admin_user or through your custom extension's model table. The main issue is your values are not being put away by your fundamental model classes, i.e. reflections of Mage_Core_Model_Abstract. Yet, why you ask subsequent to Magento should consequently induce database table to model relations through Zend_Db and enchantment getters and setters.

Clear that cache

Well, in fact the solution is pretty simple:

Zend_Db caches the structure of the database tables.

Thus, if you add new columns make sure to refresh the cache. Zend will then update the cache accordingly.

Also note that even if you all your caches are disabled the database structure and other info may still be cached in var/cache, so:

Clear /var/cache.

After that do indexing from magento admin panel.

to make sure that your table adaptions reflect properly.