Booting with Grub

[kirk abbott]

One of the things that I have been noticing lately, is that as I continue update from the original 8.04 configuration, more startup lines are showing up on grubs' boot list, with the most recent update at the top. And each update has two lines, plus two for the windows partition. 

Is there a reason for that? Do I really need each entry, or is there a way to get of redundant entries?