Can't unzip and zip Firefox addon

I'm trying to make some changes to an old Firefox addon of mine (available here). The .xpi package there works. But when I literally just unzip and rezip it, it will still install, but the context-menu-item the 开发者_开发问答addon should insert isn't here. What in the world could I be doing wrong?

dylan~/scripts$ git clone git@github.com:nospampleasemam/peepshow
dylan~/scripts$ cd peepshow
dylan~/scripts/peepshow$ rm -rf *
dylan~/scripts/peepshow$ git checkout peepshow.xpi
dylan~/scripts/peepshow$ ## at this point I can install the addon and it works.
dylan~/scripts/peepshow$ unzip peepshow.xpi
Archive:  peepshow.xpi
   creating: chrome/
   creating: chrome/skin/
   creating: chrome/content/
 extracting: chrome/skin/returntoresults.css~  
 extracting: chrome/skin/returntoresults.css  
  inflating: chrome/skin/icon.jpg    
  inflating: chrome/content/loader.js  
  inflating: chrome/content/loader.js~  
  inflating: chrome/content/overlay.xul  
 extracting: chrome/content/resultscollector.js~  
  inflating: chrome/content/overlay.xul~  
  inflating: chrome.manifest         
  inflating: icon.png                
  inflating: install.rdf             
dylan~/scripts/peepshow$ rm peepshow.xpi 
dylan~/scripts/peepshow$ zip *
  adding: defaults/ (stored 0%)
  adding: defaults/preferences/ (stored 0%)
  adding: defaults/preferences/list.js~ (stored 0%)
  adding: defaults/preferences/list.js (stored 0%)
  adding: install.rdf (deflated 54%)
  adding: chrome.manifest (deflated 41%)
dylan~/scripts/peepshow$ ls
chrome  chrome.manifest  chrome.zip  icon.png  install.rdf
dylan~/scripts/peepshow$ mv chrome.zip chrome.xpi
dylan~/scripts/peepshow$ ## now I can install chrome.xpi
dylan~/scripts/peepshow$ ## but the menu item doesn't appear.

Thanks for any help!

You need to zip sub directories as well: zip -r chrome.zip *.