It appears to work on the tracker here (also running 1.0.0a3). Have you made any customizations to your site?

I have tested creating from scratch without any customization a new Mantis environment.
I've done the test using easyphp1.7.
It doesn't works.
I've selected bugid as first colonn to sort on, but the result is still lastupdate.
I'm using the french language

I agree that it works here in your version, but the behavior on filters is quite different in your version.
In mine when I click on a criteria, I get listbox for all criteria, in your I get only a criteria for the clicked criteria.
Is-it just a parameter in config_inc.php

Hi, I encountered the same problem.
A solution is to click on the column header and next on show sort to update the second sort column.

Hope this help

I think I see the problem. There is a setting $g_dhtml_filters that controls the filter panel. If off, you get the older behaviour of a separate filter page.

Fixed in CVS.

view_filters_page.php -> 1.38