SHA256 hashes with Message

Having trouble wit the syntax to create an SHA256 hash from a string using the Message package. Works fine for the 'fallback' encryption methods - SHA1 and MD5, but the I could have done that natively in PHP without PEAR. Works fine .... $hash = Message::createHash('MD5'); echo 'MD5: '.$hash->calc($data)."\n"; Doesn't work .... $hash = Message::createHash('SHA256'); echo 'SHA256: '.$hash->calc($data)."\n"; The docs hint at a different syntax for hashing with SHA256, but I can't get it to work with any permutation of commands. Anyone got the magic command? Many thanks Kevin