Hi Tom,
It has been recommended that these Disk Permissions be verified and
repaired before and after major Software Updates. When you install
third party software and sometimes just because, these permissions
become "out of wack" and then when Software Updates are applied
various problems arise. These problems are not consistent across one
computer to the next as each of us do different things that cause
permissions to be modified and/or other system changes. That is why
the results are inconsistent when the update is applied. Some users
experience no adverse effects, others experience various problems
although most don't experience the same problem. So, in a nut-shell,
performing this permissions task before and after a major update
gives you more reliable results and less chance for problems.
Later...
Tim Kilburn
& Carter the Canine
Fort McMurray, AB Canada