I have solved the confidence men achievement glitch - help - fixed - how - whatever
a buddy of mine and i played through all levels of all activities and got all the 15 point achievements and the crime lord achievement, but no confidence men. we looked at our stats and i had 22/23 and friend had 20/23. replaying them does not work, apparently once you have played it on single player wether it was just one level or the entire activity, it is designated as being beaten on single player.
I have solved the confidence men achievement glitch - help - fixed - whatever
i know that we are not the only ones to experience this so i figured i would post the answer to the problem.
we eventually decided to start a new game, just out of curiosity we checked the stats, and under the co-op stats on last page they still had the same numbers. went to play the one i knew i had finished by myself, got the achievement, 23/23.
you must both load a completely new game. loading one new and one game that has activities completed on it does not work. it is also easier if you know which activities you may have completed solo, or possibly in a different co-op game, remember, even 1 level of 1 activity counts.
this will save you the hastle of having to play through them over and over again, discovering that nothing works (like we did).