Can't revert back to Safari 3

I installed safari 4 beta yesterday but I can't log into some accounts so I need to go back to Safari 3. However, I have just downloaded and attempted to install safari 3 but it says I've already got a newer version on the dive... so I uninstalled ALL safari application and emptied the trash and it still says that there is a version on the drive.

... What do I do ?

Thanks

NStocks