SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction by Magento position

Question

We have a problem in our Magento shop when we try to set the position of the products in a category from manage categories. When we try to save a product after changing the posi

Answer 1

The error occurs most probably because you have the product position index set to auto and Magento tries to rebuild the index along with the product save.
Go to System->Index Management and set the indexes related to catalog to 'manual'.
Then set the product positions and when you are done rebuild the indexes manually.