ubuntu 10.04 tftpd-hpa

After upgrade the Ubuntu from 9.10 to 10.04, the tftpd does not work any more.
It complained "TFTP error 2: Only absolute filenames allowed".
Here are some steps to correct this.
1. modify the /etc/default/tftpd-hpa and change the following content.
TFTP_OPTIONS="-s"
2. You might change the default tftp folder.
TFTP_DIRECTORY="/srv/tftp"
With my case, I add symbol link. "sudo ln -s /srv/tftp /tftpboot"