Help deleting data using cql v3

[Stephen Powis]

I have the following schema setup in cassandra 1.1 with cql 3:

CREATE TABLE testCol (
  my_id varchar,
  time_id TimeUUIDType,
  my_value int,
  PRIMARY KEY (my_id, time_id)
);

and the following data already inserted:

my_id        | time_id                                               |
my_value |
1_71548     | 2fc39fa0-1dd5-11b2-9b6a-395f35722afe |          1    |

but when I issue the following delete command using cqlsh -3, the data is
not removed.

delete from testCol where my_id='1_71548' and
time_id=2fc39fa0-1dd5-11b2-9b6a-395f35722afe;

Is it possible to remove data using the full composite key?  Or am I
formatting the UUID incorrectly?

Thanks!
Stephen