hope this will make Leopard as rock solid as 10.4.11, assuming its the last release.
maybe you had "Require password to unlock each System Preferences pane" ticked in Security preferences in Tiger but not in Leopard. also in non administrative accounts all the panes with padlocks are locked by default.
The amount of problems in Leopard will never make it as solid as 10.4.11. I'm very afraid that we'll never see an OS X version as solid again. Snow Leopard has its own set of problems in addition to Leopard's.