This behaviour can be fixed by your developer with a modification to the following file: <path/to/magento/>app/code/core/Mage/Adminhtml/controllers/Catalog/ProductController.php
The following code will need to be commented out, near line 700 depending on version:
Mage::getModel('catalogrule/rule')->applyAllRulesToProduct($productId);
In more recent versions of Magento (1.6.x and later), the “Manual” index mode will no longer automatically reindex after a product is saved, and any full reindexes will need to be performed manually. This is preferable, especially when adding/editing multiple products to a large catalogue.
Scheduling reindexes with Cron
As a full reindex of all the products can take several minutes, it is recommended to run the reindexing process overnight with a cron job. This will help mitigate the performance impact of reindexing a large catalogue. Cron jobs can be created from cPanel on shared hosting, or as the ‘web’ user on a VPS service. Please open a support ticket from the Client Area if you require assistance with this step.
