SQL Insert

Trying to IM with other user don't show anything to the other user. I code a watchdog:

watchdog("Ajax IM",$to_insert,$to_insert);

in ajaxim_server.module in the line 83 to see what is happening and the watchdog says:

(208, 'LOGOUT', 'msg', '1', '2', '')

But wher I go to the mysql table to look I see:

mysql> select id,recipient,sender,message from ajaxim_messages where id='208';
+-----+-----------+--------+-----------------------------------------------------------------------------------------------------------------------------+
| id | recipient | sender | message |
+-----+-----------+--------+-----------------------------------------------------------------------------------------------------------------------------+
| 208 | 0 | 0 | <span style="font-family:Tahoma,sans-serif;font-size:12px;color:rgb(0, 0, 0);">LOGOUT</span> |
+-----+-----------+--------+-----------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.03 sec)

Recipient and sender are 0????

If I do mysellf the insert but changing the recipient and sender uid with a valid uid, all the module works fine and the messages shows in the IM window.