Apparently Mozilla/5 includes Firefox 1.0. It also includes Mozilla 1.7.4. At least, that's what it tells me when I view the Help -> About links on those two browsers. I guess the 5.0 thing is an engine shared by both browsers.
I dunno about those statistics though - what's this?
3 458961 12.98% Java/1.4.1_03
What's special about that version of Java, that it accounts for 13% of our web traffic, while other versions of Java don't appear at all?