anyone know why my separator/flexiblespace/spacer aren't showing on safari 5? do you know if there is a away to add 'em back (maybe with the plist file)?
It means that Apple decided (for some ridiculous reason) not to include them in the customization pane anymore! It's actually easy to add them manually, though:
Once you've added the items, you'll even be able to drag them around when customizing your toolbar in Safari!
(This process is made a bit easier by the "Property List Editor" app included with Apple's Developer Tools. And, as always, don't forget to backup the .plist file before making any changes.)