The last Security Update killed my venerable iMac G$ so thoroughly that even reinstalling OSX hasn’t brought it back to full functionality.

And now Apple wants us to install another Security Update? Anyone who does so is taking a terrible chance. Me, I’ll never install another Apple Security Update until I know that no one else’s machine has been hosed by it.

Not a bad precaution, especially with an older system.

FWIW I’ve installed it on two systems so far, a silver and a white MacBook, running 10.5.7 and it was fine. Like you, I’m waiting to do my G5.

I’ve installed all of these updates without a hitch on G5 systems running 10.5.7. Either the first poster is flat out lying, or there is something seriously wrong with that machine.

While in general it may be a good idea to wait a few days in order to check if someone else may have had some problems with the update, this particular patch is extremely critical. Safari was wide open to serious drive-by java attacks and, in addition to the proof-of-concept site that demonstrated how simple the attack was (absolutely no action by user required to get root privileges after visiting the malicious URL), malicious sites were being reported out there. The worst part is, you just don’t even know you’ve been had by the attacker!

As for these installation problems, if you have a mission-critical machine and are anxious about updating, just do a full back-up (carbon copy cloner or similar) and update. If it’s hosed, reformat, restore and all is well.

Safari was wide open to serious drive-by java attacks

Only if you haven’t turned off Java in your preferences, which, seriously, everyone should have done if they were continuing to use Safari after the exploit was announced. Probably still a good idea to only turn it on if you have a specific need and then only when necessary.