tried reinstalling a bunch of times, tried with 1.0, tried with 1.1, i cant unlock the weapons anymore, i get the warning saying that i unlocked, so i quickly change from one weapon to another (like with the standard soldier from rifle to pistol) so that i can use the elite weapon but i didnt got it

ok i hav managed to fix the reward bug, all you have to do is get the reward weapon, then check to see if u got it. If you didnt either die or change your "loadout" (like lets say youre with the trooper, dont get the elite rifle, then change to an engineer) and get tis reward weapon. the bug should have gone now

Actually doesnt it take like 30 kills of the assault rifle to get the elite rifle?

No...it's something like 12 for Normal mode and 8 for Elite.

Ah ok, your right, thankyou bokkenblader56.