Thanks for all the info! It's very helpful.
Well there goes my first theory - lol. I was going to try to figure out what was different between the kernels in AVLinux and Mint, and the modules being loaded. But if it works on the live DVD...it sounds more like a permissions problem than a kernel problem. Using an extended partition should not cause an issue, if it does the problem is with the AVLinux/Remastersys installer and not the way you set things up.
I'd like if you could try removing gnome-network-manager and replacing it with wicd, but that's no small task given that you still don't have internet access when booted to your installed AVLinux. Two ways come to mind of accomplishing this, you could:
1. Download wicd and the required dependencies (a bunch of Python stuff) from Debian, copy them to your AVLinux computer, and install them using dpkg or gdebi. That's very slow and tedious.
2. Boot on the live DVD (or any live Linux CD), chroot into your AVLinux installation, and use apt-get to install the needed packages. But explaining that process goes a bit beyond my tech support abilities.
Before you do that though, try this:
1. Boot into the AVLinux live DVD. You should be able to navigate the root partition of your AVLinux installation.
2. Open the file manager and navigate to etc/pam.d/ (again, on your installed partition, not the live file system). In the 'tools' menu of the file manager, click 'Open current folder as root'.
3. Double-click 'slim' (that's etc/pam.d/slim) to open it with Gedit.
4. Replace the contents of etc/pam.d/slim with this:
# The PAM configuration file for the SLiM graphical login manager
# Disallows other than root logins when /etc/nologin exists
# (Replaces the `NOLOGINS_FILE' option from login.defs)
auth requisite pam_nologin.so
# This module parses environment configuration file(s)
# and also allows you to use an extended config
# file /etc/security/pam_env.conf.
# parsing /etc/environment needs "readenv=1"
session required pam_env.so readenv=1
# locale variables are also kept into /etc/default/locale in etch
# reading this file *in addition to /etc/environment* does not hurt
session required pam_env.so readenv=1 envfile=/etc/default/locale
# Standard Un*x authentication.
# This allows certain extra groups to be granted to a user
# based on things like time of day, tty, service, and user.
# Please edit /etc/security/group.conf to fit your needs
# (Replaces the `CONSOLE_GROUPS' option in login.defs)
auth optional pam_group.so
# Uncomment and edit /etc/security/time.conf if you need to set
# time restrainst on logins.
# (Replaces the `PORTTIME_CHECKS_ENAB' option from login.defs
# as well as /etc/porttime)
# account requisite pam_time.so
# Uncomment and edit /etc/security/access.conf if you need to
# set access limits.
# (Replaces /etc/login.access file)
# account required pam_access.so
# Sets up user limits according to /etc/security/limits.conf
# (Replaces the use of /etc/limits in old login)
session required pam_limits.so
# SELinux needs to intervene at login time to ensure that the process
# starts in the proper default security context.
# Uncomment the following line to enable SELinux
# session required pam_selinux.so multiple
# Standard Un*x account and session
# Allow unlocking of gnome keyring on log in
auth optional pam_gnome_keyring.so
session optional pam_gnome_keyring.so auto_start
5. Boot into the AVLinux installation and see if that made any difference. If it didn't we'll either need to try one of the first things I mentioned above, or try to find a way to create a network connection as root.