timezone changes cause messages to be shown out of order

Experienced in vivid r112 on mako.

1. Set receiving phone's timezone to London, England
2. Send "Test 1" message to receiving phone
3. Set receiving phone's timezone to New York, NY
4. Sent "Test 2" message to receiving phone
5. Set receiving phone's timezone to San Francisco, CA
6. Sent "Test 3" message to receiving phone

Expected result: receiving phone should show "Test 1", "Test 2", "Test 3"

Actual result: receiving phone shows "Test 3", "Test 2", "Test 1" (screenshot: http://i.imgur.com/cIb3eeG.jpg)

To make matters worse, if there are enough "future" messages to fill the screen, then newly-sent messages will be inserted in scrollback, giving no user-visible sign that the message was sent. Then when the user gets a response, that isn't visible either! Hilarity ensues until the user realizes the timezone might be to blame and scrolls back. :)