You were right. Thanks a lot for your help.
# file neroAacEnc
neroAacEnc: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, stripped
Will try to install those 32 bits libs.
EDIT:
# apt-get install lib32stdc++6
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
lib32gcc1 libc6-i386
The following NEW packages will be installed:
lib32gcc1 lib32stdc++6 libc6-i386
0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 4,208 kB of archives.
After this operation, 10.8 MB of additional disk space will be used.
Do you want to continue [Y/n]? Y
Get:1
http://ftp.fr.debian.org/debian/ squeeze/main libc6-i386 amd64 2.11.2-10 [3,805 kB]
Get:2
http://ftp.fr.debian.org/debian/ squeeze/main lib32gcc1 amd64 1:4.4.5-8 [55.2 kB]
Get:3
http://ftp.fr.debian.org/debian/ squeeze/main lib32stdc++6 amd64 4.4.5-8 [347 kB]
Fetched 4,208 kB in 9s (443 kB/s)
Selecting previously deselected package libc6-i386.
(Reading database ... 32062 files and directories currently installed.)
Unpacking libc6-i386 (from .../libc6-i386_2.11.2-10_amd64.deb) ...
Selecting previously deselected package lib32gcc1.
Unpacking lib32gcc1 (from .../lib32gcc1_1%3a4.4.5-8_amd64.deb) ...
Selecting previously deselected package lib32stdc++6.
Unpacking lib32stdc++6 (from .../lib32stdc++6_4.4.5-8_amd64.deb) ...
Setting up libc6-i386 (2.11.2-10) ...
Setting up lib32gcc1 (1:4.4.5-8) ...
Setting up lib32stdc++6 (4.4.5-8) ...
# neroAacEnc
*************************************************************
* *
* Nero AAC Encoder *
* Copyright 2009 Nero AG *
* All Rights Reserved Worldwide *
* *
* Package build date: Feb 18 2010 *
* Package version: 1.5.4.0 *
* *
* See -help for a complete list of available parameters. *
* *
*************************************************************