[syslinux] tftpboot 2 clients same time

[sinan ,]

hi everybody.
im using tftp - hpa running on Debian (Sarge) GNU Linux. my problem is
about 2 clients when getting same kernel image at same time ! this
thing happens in my home, but same system works at my work. when i
want to boot up 2 clients via network i see boot message and then they
crashes and give an error message ; Unable to mount root .... kernel
panic ! ...
my both switches allows to pass the udp packets, there is not packet
filtering, discarding or blocking.
Thanks.