Complile Error

[Steve Boris <zboris ptdprolog net>]

I'm just getting started with GTK and I tried compiling the helloworld 
program to see if my system( RedHat 7.1 ) is configured correctly and I get 
this error message

gcc -g -Wall `gtk-config --cflags` -L/usr/lib -L/usr/X11R6/lib  helloworld.o 
-lgtk -lgdk -lglib -lX11 -lXext -lm  -o helloworld
/usr/lib/libgtk.so: undefined reference to `atexit@@GLIBC_2.0'
collect2: ld returned 1 exit status
make: *** [helloworld] Error 1

Can anyone tell me why there is a reference to glibc 2.0 when I know that I 
do not have it installed on my system.

This error also occurs when I try to compile someone else's program.

Any help would be great !!!
Thanks