Composer not working on AWS Ubuntu server, locally works fine - symfony-1.4

Question

Composer install command works fine locally on my computer:
Loading composer repositories with package information
Installing dependencies from lock file
Nothing to install or update
Generating autoload files
When I connect via ssh to the ubuntu server, and run the same command I get this.
PHP Fatal error: Class 'Composer\Installers\Installer' not found in phar:///usr/local/bin/composer/src/Composer/Installer/InstallerInstaller.php on line 102
Fatal error: Class 'Composer\Installers\Installer' not found in phar:///usr/local/bin/composer/src/Composer/Installer/InstallerInstaller.php on line 102
I followed the instructions here for both machines:
https://github.com/composer/composer/blob/master/README.md
I am missing some dependencies here? I can't figure out why that error.
Edit: Here is the .json (project is symfony 1.4, adding tags as well)
{
"minimum-stability": "dev",
"require" : {
"snappy/sfSnappyPlugin": "*"
},
"repositories": [
{
"type": "git",
"url": "https://github.com/FloranBrutel/sfSnappyPlugin.git"
}
]
}
Edit2: The output of the php -v on the AWS server
PHP 5.3.10-1ubuntu3.4 with Suhosin-Patch (cli) (built: Sep 12 2012 18:59:41)
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies
On my machine I have:
PHP 5.3.6-13ubuntu3.9 with Suhosin-Patch (cli) (built: Sep 12 2012 19:00:27)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
with Xdebug v2.1.0, Copyright (c) 2002-2010, by Derick Rethans

Answer 1

I have managed to replicate your problem. Within the directory you are running composer, you should have a path like so:
vendor/composer/installers/src/Composer/Installers
and within this directory there should exist an Installer.php file. I managed to get the same error you are getting by deleting that one file.
So I believe a solution would be to simply completely remove your vendor and plugins directories and try running composer install again, forcing the complete re-download of all the vendors in your composer.json. Hope this helps.

Answer 2

What are the exact commands you run?
What you should do:
run rm -rf vendor/* to erase all possible composer data (it use vendor/.composer as a cache)
run composer self-update to update Composer to it latest. Does this works?
try composer -V
make sure you have openSsl on the server (as you are requiring over https)
switch APC to false on the cli apc.enable_cli=0