Strange SELECT lock / timeout (1 reply)

I'm having a strange problem with a SELECT in an Innodb table, it never returns.

CREATE TABLE `example` (
`id` int(11) NOT NULL,
`done` tinyint(2) NOT NULL DEFAULT '0',
`agent` tinyint(4) NOT NULL DEFAULT '0',
`text` varchar(256) NOT NULL,
PRIMARY KEY (`id`),
KEY `da_idx` (`done`,`agent`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |


The query that I can't obtain the results is:
SELECT id, text FROM example WHERE done = 0 AND agent = 0 LIMIT 120;

First I thought in some index optimization or lock problem, I was some time researching that but then I found this:

SELECT id FROM example WHERE done = 0 AND agent = 0 LIMIT 120;
...
...
...
120 rows in set (0.27 sec)


SELECT text FROM example WHERE done = 0 AND agent = 0 LIMIT 120;
...
...
...
120 rows in set (0.83 sec)

Now I'm lost, how obtaining id or text column separately with exactly the same query (same WHERE and LIMIT) works perfect and then obtaining both of them not??

Executing the "SELECT id, text..." again after that two queries have the same effect, never returns.