Why do I get the Invalid UUID string when updating Cassandra column metadata?

I am trying to define a circuit in Cassandra 0.7 and would appreciate a solution to the problem that I am facing. I created a supercolumn family in cassandra-cli:

create column family SimulationSummary with column_type='Super' and comparator='LexicalUUIDType'and subcomparator='TimeUUIDType';

It succeeds. However, when I try to update the metadata column family:

update column family SimulationSummary with column_metadata=
...   [{column_name: underlying, validation_class:BytesType}];

I get an error message:

Invalid UUID String: underlying

This is a representative problem of several other column families (some of them are not super-column families).

I have several column family metadata updates that work fine, but I could not determine why some records are working fine and others not. For example, the following is done:

create column family User
  with comparator='UTF8Type';
update column family User with column_metadata=
[
  {column_name: email, validation_class:UTF8Type},
  {column_name: given_name, validation_class:UTF8Type},
  {column_name: surname, validation_class:UTF8Type}
];