mysql torrent1> SELECT id, unread FROM messages WHERE receiver=60505 ORDER BY id DESC LIMIT 0,10;
+---------+--------+
| id      | unread |
+---------+--------+
| 3144053 | no     |
| 3143147 | no     | - 3143803 missing
| 3142989 | no     | - 3142237 missing - 3142171 missing..etc
| 3141997 | no     |
| 3141945 | no     |
| 3141795 | no     |
| 3141053 | no     |
| 3141035 | no     |
| 3140863 | no     |
| 3140629 | no     |
+---------+--------+
10 rows in set (0.00 sec)

mysql torrent1> SELECT id, unread FROM messages WHERE receiver=60505 AND unread='yes' ORDER BY id DESC LIMIT 0,10;
+---------+--------+
| id      | unread |
+---------+--------+
| 3141863 | yes    | - why it doesn't appear at first q. answers ?
| 3142237 | yes    | - why it doesn't appear at first q. answers ?
| 3143803 | yes    | - why it doesn't appear at first q. answers ?
| 3142171 | yes    | - why it doesn't appear at first q. answers ?
| 3142167 | yes    | - why it doesn't appear at first q. answers ?..
| 3141889 | yes    |
| 3140939 | yes    |
| 3141925 | yes    |
+---------+--------+
8 rows in set (0.01 sec)

Second bug, look at sorting of second q. results..