From all of my research, Safari 4.1.x was released as a port of Safari 5.0.x for Mac OS X 10.4. Both have the same WebKit versions, and the same release dates. The only difference I can find is that Safari 5 has a few more added features like Development Tools, Bing Search, and others that we wouldn't really track here in BCD.

I'm thinking we should simply drop Safari 4.1 out of our data to reduce confusion.