It never was necessary. Did you mean vendor prefixes?
Safari 5 is pretty old now, and I doubt it’s widely used any more. Anyhow, Safari has not needed vendor prefixes since version 5. I don’t remember, but perhaps version 5 was a bit buggy?
Hi, JamesICT. I have a shot-in-the-dark suggestion… (I don’t have a Mac).
Your custom stylesheet should be the last stylesheet in the lineup, not the first (or anywhere near it). My clue was the number of !important modifiers in it. They shouldn’t be necessary. If the custom stylesheet were last, they wouldn’t be. It would do its thing in the cascade and override previous styles of equal or less specificity. So the suggestion is to relocate your custom stylesheet, remove the !important modifiers, and see what happens. You may indeed need one or two of the modifiers, but not most. And with luck, you might fix the border-radius issue.
Is Safari Apples’ way of trying to one-up Microsoft for releasing the most O/S specific browsers with its systems, or was Safari 5 a lemon, or is it significantly outdated? :p[/ot]