The general inability to re-arrange items appears to be intentional. The reason is that (as cited on several threads in Apples Discussion boards - although not officially confirmed by Apple) Login Items now load asynchronously (this started in Panther). In brief, this means that Login Item #2 will launch immediately after Login Item #1 has launched, even if #1 has not yet completed its launch (and so on for other items). This is similar to what happens if you click several items in succession from the Dock. They all seem to be launching at once. Depending on what the items are, Item #2 may actually finish launching before Item #1. The end result is that the load order becomes largely irrelevant.
Despite all this, if you still want to control the listed load order of your Login Items (perhaps because Item #2 needs information from Item #1 in order to launch successfully and the correct load order at least gives this a chance of happening), you do have a few options. These include:
* Bypass using Login Items at all - except for a single Automator workflow application. Have the Automator workflow set up to launch the desired items in the order you wish. Using the Finders Launch Application action in Automator should make this easy to do.
* You can delete and re-add items in the Login Items list. Added items appear as the last item in the list, allowing for a crude but effective method of re-ordering items.
