What is your version of the syslinux package?
dpkg -l syslinux
If this happens to you with the latest version of syslinux (currently 2:3.63+dfsg-2ubuntu3),
and it doesn't happen if you use an earlier version (e.g. trying copying pxelinux.0 from Jaunty),
then you should report this bug to the syslinux package, not in ltsp. Thanks!
What is your version of the syslinux package?
dpkg -l syslinux
If this happens to you with the latest version of syslinux (currently 2:3.63+ dfsg-2ubuntu3) ,
and it doesn't happen if you use an earlier version (e.g. trying copying pxelinux.0 from Jaunty),
then you should report this bug to the syslinux package, not in ltsp. Thanks!