Bizarre Error 28 From Storage Engine

I am getting error28 from storage engine with every application using mysql. The issue started a few weeks ago so i thought emptying /tmp folder would solve the issue but it didn't . Problem seems to disappear when i reboot the server but problem comes back again after a few hours . I even got tmp partition deleted and recreated

I enclosed some info from server below

root@latte [~]# stat /tmp
File: `/tmp'
Size: 81920 Blocks: 162 IO Block: 4096 directory
Device: 700h/1792d Inode: 2 Links: 4
Access: (1777/drwxrwxrwt) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2009-10-28 22:39:38.000000000 +0000
Modify: 2009-10-28 22:39:35.000000000 +0000
Change: 2009-10-28 22:39:35.000000000 +0000

root@latte [~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 143G 42G 94G 31% /
tmpfs 502M 0 502M 0% /dev/shm
/usr/tmpDSK 485M 12M 449M 3% /tmp

root@latte [~]# du -hsx /tmp
1.2M /tmp

root@latte [~]# mysqladmin variables | grep -i "log_error"
| log_error | |

root@latte [~]# find /var/lib/mysql -iname "*.err"
/var/lib/mysql/latte.quicklyweb.net.err

less /var/lib/mysql/latte.quicklyweb.net.err
091028 2:13:57 [ERROR] /usr/sbin/mysqld: Disk is full writing '/tmp/STH2JAx1' (Errcode: 28). Waiting for someone to free space... (Expect u
p to 60 secs delay for server to continue after freeing disk space)
091028 2:13:57 [ERROR] /usr/sbin/mysqld: Retry in 60 secs. Message reprinted in 600 secs
091028 2:23:57 [ERROR] /usr/sbin/mysqld: Retry in 60 secs. Message reprinted in 600 secs ....