Magento

Hello I have a big problem, cannot edit/add customer on admin panel after upgrade from 1.5.0.1 to 1.5.1.0, PLEASE HELP

Error message
Fatal error: Call to undefined method Mage_Customer_Helper_Data::getNamePrefixOptions() in /home/artdeviv/www/app/code/core/Mage/Adminhtml/Block/Customer/Edit/Tab/Account.php on line 87

thank you

First question: Did you delete your cache?

Second; if that doesn’t work you might want to re-install your core adminhtml to see if the install missed something

Yes to cache files and I also replaced by the new admin folder and it always gives me the same error. I also did a verification of the customer database and I see nothing. I do not understand the problem is that the management of customer.
Thank.

Do you have any custom modules installed that would override the core code?

Do you have any admin modifications that had been done and over written on updates?

Looks like a 3rd party extensions was installed on the last installation, which modified customer edit data part.