Raimundo, The system was correct. The flight you are trying to file is AAL1049. That is not in your FREQ. Look at the list and you will see that AA1049 is. The FREQ shows all AA letters and that is EXACTLY the way it should be filed for the FREP. Now if you want to fly on VATSIM using the AAL that is your choice, but you must file it exactly like your FREQ shows.
If you ever think you have problems please e-mail your HUB manager for help as he can take care of most problems.