Magento Catalog Price Rules bugs
Magento's "Catalog Price Rules" was always a buggy experience, ever since magento 1.3... I don't know what's going with the development, but it's still buggy up to 1.4.1 ...
So here are a couple of fixes I found.
Magento 1.4.0.1:
source: http://www.magentocommerce.com/boards/viewthread/194930/#t245120
1. Open up Observer.php in /app/code/core/Mage/CatalogRule/Model/
2. Find the dailyCatalogUpdate() method
3. At the end of the method, before “return $this;”, add:
$this->applyAllRules( $this );
4. (Not sure if this step is necessary) Open up /app/code/core/Mage/CatalogRule/etc/config.xml
5. Find the crontab > jobs > catalogrule_apply_all area
6. Change
<cron_expr>0 1 * * *</cron_expr>