QUOTE(Mark K @ Jun 2 2008, 02:07 AM)

I just tried to install version 3.1.1 but when installing it said it requires OS X version 10.5.2, and I am still using 10.5.1

Update to 10.5.3, it has Safari 3.1.1 in it
Btw, there's NO significant difference between 3.1 and 3.1.1.