Bastard Child Browsers

Is there a bastard child (majority usage, but not standards compliant) of the current Apple Safari browser as IE6 is the bastard child of IE7? The current Safari is rendering my CSS identical to FF - all except for when you apply Scriptaculous scroll down effect to a fixed position DIV. I just have to make sure because it seems too good to be true…

Also, I am having trouble using IE6 standalone. It won’t let me view sites which require logins. I do have cookies enabled.