?chown and ?chown32 syscalls

In asm/unistd.h there are 2 series of syscalls for chown commands (chown, lchown and fchown) : the ?chown and ?chown32
In 2.4.17 (ix86) the system is using the ?chown32 syscalls, when I intercept the ?chown syscalls nothing happens. Are these syscalls deprecated ?

Thanks for any help.
Laurent Sinitambirivoutin
[email protected]

PS: please CC: me the answers since I'm not on the list... ;)