Shellcode on Fedora Core 2

[five40]

Does anyone know why a normal execve syscall doesn't work in fedora core 2? I upgraded from RH9 and my code no longer works. I recompiled my assembly code, get the opcodes, updated my C code with the new opcodes and when I run I get seg faults. Does anyone know if something has changed in the kernel in core 2 as to why my code won't work?