It sounds like you don't have the analysis toolpack up and running. Double check to see that you do. Make sure on the options page that you have the options selected that you want.
When you add rows to the gear list, don't forget to "drag" the formatting of the rows above down.
Lastly, make certain that you "select all" and "sort" after you've made changes to the gear lists.
It's a great spreadsheet, but can be a bit fiddly at first.