cant get r6 v2 realistic achievement

[Ka1n007]

I have completed the game on realistic and am able to verify it by looking at every section of the map and see realistic checked off but am not able to get my achievement. The only reason I didnt play it all the way thru the 1st time is bc half way xbox live went dead at like 3 am. I was not able to finish until a day later. Resuming where i left off and finishing the game I still cannot get it. Ive done the final level and the level xbox live crashed on fully over again and still cant get it? help ?

[razzleson]

For questions about a specific game, try that game's forum.

Here's a thread specifically on the problem you're having:
http://www.xbox360achievements.org/forum/showthread.php?t=63264

Enjoy!