Halo 2.5 on 1.6

[threeballspin]

I tried to put halo 2.5/halo 2 ce on my buddy's 1.6 and it won't work. Did everything in the proper way. Copied all the maps to the computer, patched them, singed them, and ftp'ed them back. And it didn't work. Then just to test we put them on a clean version of halo2 on my xbox and it worked perfectly. Mine is a 1.3. Has anyone else had this problem/ found a fix? Thanks in advance.