strange system resource limits

[Friedrich Locke]

Hi,

i have setted my system resources for a given user via login.conf, but
after the user login the ulimit -a returns different values.

Here is my login.conf entry:

general:\
        :coredumpsize=infinity:\
        :cputime=infinity:\
        :datasize=infinity:\
        :filesize=infinity:\
        :stacksize=infinity:\
        :maxproc=infinity:\
        :memorylocked=infinity:\
        :memoryuse=infinity:\
        :openfiles=infinity:\
        :vmemoryuse=infinity:\
        :auth=krb5-or-pwd:\
        :ignorenologin:\
        :localcipher=blowfish,6:\
        :ypcipher=old:\
        :priority=-5:\
        :ftp-chroot:\
        :tc=default:

But when i log in, what i get for ulimit is:

sioux@gustav$ ulimit -a
time(cpu-seconds)    unlimited
file(blocks)         unlimited
coredump(blocks)     unlimited
data(kbytes)         8388608
stack(kbytes)        32768
lockedmem(kbytes)    unlimited
memory(kbytes)       unlimited
nofiles(descriptors) 7030
processes            1310


My doubt is why data and stack limits are not infinity ?

Thanks in advance.