Magento error 623 - Calling parameters do not match signature

It looks like you have come upon a known Magento bug that could be easily solved from your end, by commenting out two lines of code.

Please follow these guidelines - 

1. Open the file lib/Zend/XmlRpc/Server.php (it should be located at the root Magento directory).
2. Find the piece of code

3. And comment it out

For a reference, see - 

http://www.magentocommerce.com/boards/viewthread/40743/