MySQL: GROUP BY Latest record - not showing some records

Question

I have a mysql table with the following structure:

id | fuid | tuid | msg | time | new
-- -- -- -- -- -- -- - -- -- -- -- -- - -- -- 
1 | 58 | 6 | test msg |2014-07-29 12:06:45 | 1
2 | 18 | 6 | test msg |2014-07-29 11:38:00 | 1
3 | 58 | 6 | test msg |2014-07-29 11:38:00 | 1
4 | 58 | 6 | test msg |2014-07-28 17:08:54 | 1
5 | 58 | 6 | test msg |2014-07-28 17:08:48 | 0
6 | 39 | 6 | test msg |2014-07-28 16:47:54| 0
7 | 21 | 6 | test msg |2014-07-28 16:37:40| 0
8 | 83 | 6 | test msg |2014-07-28 16:33:35| 0
9 | 83 | 6 | test msg |2014-07-28 16:32:51| 1
10 | 83 | 6 | test msg |2014-07-28 16:32:45| 1

Where fuid = from user id (allow duplicates), tuid = to user id (allow duplicates), new = status (read or not).

I'm trying to retrieve the latest new messages (new = 1) grouped by fuid with this query:

SELECT ch1.* 
FROM chat_history ch1 INNER JOIN 
(
    SELECT fuid, MAX(`time`) as `time` 
    FROM chat_history 
    GROUP BY fuid
) ch2 
ON ch1.fuid=ch2.fuid AND ch1.time=ch2.time 
WHERE ch1.new=1 AND ch1.tuid=6 
ORDER BY ch1.time DESC

... and the latest read messages (changing ch1.new = 0).

The problem: for new=1 i don't get records with fuid=83 and for new=0 i don't get records with fuid=58.

I don't get this behaviour and I cannot find a solution.