correct way to cvsup ports for -stable

Hi! A similar topic has been disscused here several days ago, but I still don't understand, how correctly update ports tree via cvsup. I have installed 4.9-release. I upgraded to -stable according to /usr/share/examples/cvsup/stable-supfile (I have changed only '*default host=...' line, all rest I

problem with mounting cd: "cd9660: /dev/acd0c: Invalid argument:"

s source tree and make buildworld/buildkernel/installkernel/installworld (kernel and rest system are sync). Before upgrade mentioned above everything worked well. I run 'MAKEDEV all' from mergemaster after installing new kernel & world. I forgot something? Thank you for any advices.