Tyson77,

ICE is going through a lot of restructuring and having a great difficulty balancing its budget.  While I am not sure exactly why they rejected you, it probably has more to do with a restructuring of the duties of the position which in turn changed the qualifications.  Also, theymay have changed the test format or a million other things which would have made a change in the process and thus affected anyone already in the process.

I really wouldn't fret all that much, ICE and CBP are very likely to continue to open up positions next year.  Case in point IEA's only progress to GS-9, but CBP officers and Border Patrol agents progress to GS-11.   

I am also sure that with the addition of 2000 beds to ICE detention facilities you will also see an increase in the need for more IEA's and more subsequent openings.

As for the question you posed "Why would I apply for a job I am already being considered for?"  My reply is welcome to the modern marvel of inefficiecy called the Federal Gov't.

In all seriousness, don't give up and be patient.