If you have Solstice SyMON currently installed on your system, you should remove the SyMON packages before installing or upgrading to Solaris 7. The packages you should remove are:
SUNWsyc
SUNWsye
SUNWsym
SUNWsyrt
SUNWsys
SUNWsyu
SUNWsyua
SUNWsyub
SUNWsyuc
SUNWsyud
SUNWsyue
SUNWsyuf