Glib Fix not working

./ns2server debug
[ INFO ] Debug ns2-server: Glibc fix: Using Glibc fix
        * glibc required: 2.15
        * glibc installed: 2.13

Natural Selection 2 Debug
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Distro: Debian GNU/Linux 7.11 (wheezy)
Arch: x86_64
Kernel: 3.2.41-042stab116.2
Hostname: xxx.[hoster].de

Start parameters:
./server_linux32 -name "xxxx" -port 27015 -webadmin -webdomain xxx.xxx.xxx.xxx -webuser xxxx -webpassword "xxxx" -webport 16000 -map ns2_summit -limit 16 -config_path "/home/ns2server/server1" -modstorage "/home/ns2server/server1/Workshop"

Use for identifying server issues only!
Press CTRL+c to drop out of debug mode.
Warning! If ns2-server is already running it will be stopped.

Continue? [Y/n]y
[ INFO ] Debug ns2-server: Stopping any running servers
[  OK  ] Stopping ns2-server: xxxx is already stopped
[  OK  ] Debug ns2-server: Starting debug
./server_linux32: /lib/i386-linux-gnu/libm.so.6: version `GLIBC_2.15' not found (required by /home/ns2server/serverfiles/libSpark_Physics.so)
./server_linux32: /lib/i386-linux-gnu/libc.so.6: version `GLIBC_2.15' not found (required by /home/ns2server/serverfiles/libSpark_Network.so)