0.6.2.

* user double-submitted the same message text to an 
issue
* in the Web interface, I hit Remove on the most recent 
duplicate message in the issue
* the duplicate was removed, but the ordering of the 
existing messages on the issue changed

Before Remove:

msg586, msg843, msg852, msg1743, msg1747, msg1748, 
msg1750, msg1751

After Remove on msg1751:

msg1743, msg1747, msg1748, msg1750, msg586, 
msg843, msg852

Looks almost as if it's doing an alpha, not numeric, sort: 
the shift from 3-digit to 4-digit issue numbers has 
thrown it.