Use >= instead of ^ because other packages do.

package.json

@@ -13,6 +13,6 @@
     "morgan": ">= 1.0.0",
     "cookie": ">= 0.1.0",
     "jade": ">= 1.3.0",
-    "socket.io": "^1.0.6"
+    "socket.io": ">= 1.0.6"
   }
 }