What does this button do ?- Achievement locked but Target complete

[SAVAGEDNA57]

Hi Misters and misses.

So as the title of this post explain, this achievement stay locked since i played on xbox360 of one of my friends;

So, for persuading me to buy the Season Pass and including all extension, i could have a glimse of the news maps, skins and characters of GOW3.

But for playing compfortably on two screens (Not Split), we needed 2xbox 360, so my friend install and download this season pass and extensions on his 2nd xbox.

Firstly, We start the game, i notice who my friend must sign in on 2nd xbox to activate the season pass which allow me to play on.
Secondly, i notice when i sign in with my gamertag, the achievements can not be
unlocked but the maps are available.

So i decide to continue to play without the SEASON PASS, and begin a game in Horde mode.

After playing a lot of waves, and having to play with the SILVERBACK, I complete one of this targets :
Killed 500 locusts with the rockets.

But the problem, it's today. I have the SEASON PASS and this achievement stay locked.

STATS SILVERBACK 2088kills and LEVEL 5
Target : V complete in the list

Please, thanks for help and advices.

Information : Cash system is cleaning, Playerdata and Campain deleted and re-downloaded, (Season pass and horde commandemant Pack too)

[Shockwave IIC]

Okay, you both have season pass?

Your friend downloaded the Horde command pack and hosted a Horde game. But you at this point, have NOT downloaded the Horde command pack?

[SAVAGEDNA57]

Today, I ve got the SEASON PASS and including all extension.

I completed the target of this achievement on his 2nd xbox, so before buying the SEason PAss, with the Silverback of one my friends cause i did'nt unlock the rocket of the Silverback still.

Shockwave IIC : Yeah sometimes, my friend hosted the horde game. But we didn''t play on the same his xbox.

Up!

[SAVAGEDNA57]

UP!! Please, stop working on Judgement!! But Update GEARS 3 !!

[SAVAGEDNA57]

I don't forget the work of EPIC on Gears 2 with sh*t gameplay and virtual lag, so don't forget us on Gears 3 !!

[SAVAGEDNA57]

Okay, you both have season pass?

Your friend downloaded the Horde command pack and hosted a Horde game. But you at this point, have NOT downloaded the Horde command pack?

At this point, i just practice and fight in horde on his xbox, but I have NOT downloaded the HOrde COmmand PAck still.

I download it only after 2weeks on my Xbox.

[A Crunchy Plum]

I know that there is a known problem, that if you get the 500 kills with the SB, BEFORE you download the HCP, the achievement won't unlock.

[SAVAGEDNA57]

Is it possible to reset the kills made by the silverback rocket ?

Or update stats and awards, cause in warjounal on website GOW.com, this achievement is unlocked and on my Profil LIVE, it 's NOT.

Or add a new target for this achievement : 500 kills with the Minigun turret of the SilverBack ?!

[SAVAGEDNA57]

DELETE Silverback stats (kills or/and levels) or/and
RESET, or/and
UPDATE stats and awards on LIVE and Website, or/and finally,

for me the best : ADD a new target for What does this button do? : Kills with minigun turret of Silverback