As I noted, my system seems to have updated happily.  I started it from 
yumex by enabling the rolling repos.  But I've just been examining my 
grandson's, which yesterday 'welcomed' him to emergency mode. I'm afraid 
he doesn't fit the SL target user profile and his access time is limited.

yum history shows 531 packages auto-updated two days ago, but clearly 
the process was interrupted and I'm not familiar with enabling net 
access on a broken system.  I'm hoping that I shall be able to use a 7.3 
installation disk to recover.

John P