tftp server zero-ed files sizes ?

Hi, I have a weird problem with tftp looking for some pointers:
Running : 2.4.21-27.0.1.EL Linux
/etc/xinetd.d/tftp content:
service tftp
{
disable = no
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/in.tftpd
server_args = -c -s /tftpboot
per_source = 11
cps = 100 2
flags = IPv4
}
rpm -q tftp : tftp-0.40-1

When ever I try to tftp file to it, the file will last a few secs,
and then goes from what ever sizes it is to 0 bytes.
chkconfig --list showed only 1 instance of tftp: on

If I try to put the file twice:
tftp server
tftp> put a.file
tftp> put a.file
then the file will stick (most of the time)

If I tried to put multiple files: a, b ,c at the same time in order,
the content of a usually is from b, the content of b is from c, and c is zeroed byte.

Weird behavior that I couldn't seem to google for: anyone had a fix or know what's wrong ?
Thanks.