I'm pretty sure that you are only authorized one regardless of the two award letters. And I say this because of the following statement in AR 600-8-22.
e. Award of the CAB is authorized from 18 September 2001 to a date to be determined. Award for qualifying
service in any previous conflict is not authorized.
f. Second and subsequent awards of the CAB are as follows:
(1) Only one CAB may be awarded during a qualifying period.
So even with the two award letters, one is more or less no good. Just like air assault b4 cav said. I'd go to S1 and have them remove the extra CAB from your ERB so when it does go up in front of a board you don't get gigged for having the wrong info. on it.