I think it does; however, the
Disk Utility is a "static" program in that it exists, in time, when it was loaded to your disk you use. I am unaware whether or not the Disk Utility in your own Applications "Utilities" is updated.
Does that matter? Hell if I know, but I have been told and read that it
may mess a bit with
other applications. It makes sense to me--you have a DU from a 10.5 disk is it going to screw up 10.5.5 programs?
However, why mess with that? Goeth thou to either
Onyx--a free program--or
Cocktail--as shareware and use those. Both will not only repair permissions, they will do a lot of others things to keep your Mac happy.
Now, if you have 10.5+ repairing permissions in any of those programs--DU, O, C--will take a LONG time . . . Looooooong time. If you "click" on the program in your Dock you may see the "Application Not Responding" and think it has crashed. Rest assur'd it has not.
--J.D.