Some customers are seeing an issue with Magento 126.96.36.199 but actually I think it can be any version above 1.9.1
Step 1: Open This file /app/code/core/Mage/Customer/Model/Customer.php
Step 2: Find This line in Customer.php $confirmation = $this->getPasswordConfirmation();
Step 3: Replace That that line with $confirmation = $this->getConfirmation();
Obviously any changes should be made within app/code/local rather than app/code/core so copy the file to that folder first.