Not yet fixed in 1.1.1, although target version is 1.1.0rc3? Did you forget about this issue?

Resolution on 1.1.2 Stable :

Open core/version_api.php

Goto line 130 :

change $c_date_order = db_now();
into $c_date_order = db_date();

Goto line 132 :

change $c_date_order = db_timestamp( $p_date_order );
into $c_date_order = db_date( $p_date_order );

Goto line 142 :

change " . $c_date_order . "
into '" . $c_date_order . "'

That's it! =)

i try and seems not working corretly on 1.1.2 nor when I add a version nor when I copy a version from other project.
This is what I did and seems to work even if I'm not an expert of php..but i'm lucky! :)

change line 132 to:
$c_date_order = db_timestamp(db_date( $p_date_order ));
from the original:
db_timestamp( $p_date_order );

nothing else

I'm not sure what the original issue was, but as far as I can tell there are no issues with the date order in current MantisBT versions (>= 1.2) so I'm resolving the issue.

Feel free to reopen and provide clarification if you feel this is not fixed.