近两天频繁出现这样的错误！

080905  6:36:07 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:36:12 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 15180688 bytes)
080905  6:36:12 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:36:53 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 15180688 bytes)
080905  6:36:53 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:36:58 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 15180688 bytes)
080905  6:36:58 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:37:07 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 15180688 bytes)
080905  6:37:07 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:39:29 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 14875140 bytes)
080905  6:39:29 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:40:39 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 13298945 bytes)
080905  6:40:39 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:41:43 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 14395480 bytes)
080905  6:41:43 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:44:29 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 14875140 bytes)
080905  6:44:29 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:44:42 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 10339252 bytes)
080905  6:44:42 [ERROR] /usr/sbin/mysqld: Sort aborted
080905  6:44:42 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 11267184 bytes)
080905  6:44:42 [ERROR] /usr/sbin/mysqld: Sort aborted

####my.cnf####
client]
port          = 3306
socket       = /opt/mysql/mysql.sock

[mysqld]
port          = 3306
socket       = /opt/mysql/mysql.sock
datadir       = /usr/local/mysql
open_files_limit = 8192
interactive_timeout=300
wait_timeout=300
default-storage-engine = INNODB
lower_case_table_names = 1

back_log = 500
skip-name-resolve

max_connections = 1024
max_connect_errors = 50
table_cache = 4096
max_allowed_packet = 64M
binlog_cache_size = 8M
max_heap_table_size = 128M
tmp_table_size = 128M
sort_buffer_size = 16M
join_buffer_size = 32M
thread_cache_size = 128
thread_concurrency = 8
query_cache_type = 1
query_cache_size = 512M
query_cache_limit = 16M
ft_min_word_len = 4
thread_stack = 192K
transaction_isolation = REPEATABLE-READ

log          = /var/lib/mysql/log/log
log-slow-queries= /var/lib/mysql/log/bbs-slow.log
long_query_time = 5
log_long_format

log-bin       = /var/lib/mysql/binlog/bbs-bin
server-id    = 203
binlog-do-db = cci
binlog-do-db = cge
binlog-do-db = logbbs

relay-log = /var/lib/mysql/binlog/bbs-relay-bin1
log-warnings
skip-slave-start

key_buffer_size = 24M
read_buffer_size = 2M
read_rnd_buffer_size = 16M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 64M
myisam_max_sort_file_size = 10G
myisam_max_extra_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover

skip-bdb

innodb_additional_mem_pool_size = 100M
innodb_buffer_pool_size = 1G
innodb_data_file_path = ibdata1:1000M;ibdata2:1000M:autoextend
innodb_data_home_dir = /opt/mysql/
innodb_file_io_threads = 4
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 8M
innodb_log_file_size = 200M
innodb_log_files_in_group = 2
innodb_log_group_home_dir = /opt/mysql/
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash

[isamchk]
key_buffer = 128M
sort_buffer_size = 128M
read_buffer = 8M
write_buffer = 8M

[myisamchk]
key_buffer = 128M
sort_buffer_size = 128M
read_buffer = 8M
write_buffer = 8M

[mysqlhotcopy]
interactive-timeout

[mysqld_safe]