1- first step, excuse me for my mistake uploading the wrong file 
2- download the file attached to this comment: xbee_v8x13_firmwarehack.zip
3- download the XCTU ver 5.1.0.0 from http://www.digi.com/support/productdetail?pid=3352&osvid=57&type=cabling
4- install it ,but answer No when it ask you to look for new updates
5- open xctu, go to Modem configuration
6- select your device in Modem: XB24 for normal series1 XBP24 for pro
7- notice that you have only the standard Function Set to choose (for the time being... ]:))
8- press Download new versions... and a new window will appear
9- press File... and select the new and right file uploaded here, then Ok, then Done
A- select your device in Modem: XB24 for normal series1 XBP24 for pro
B- now you have 4 more Function Set to choose, from 8013 to 8313 ]
] ] ]
C- remember it's just a official beta version without support and hard to get: http://www.digi.com/support/kbase/kbaseresultdetl?id=2182#Version 8.x.1.3
xbee_v8x13_firmwarehack.zip (1.09 MB)