I ran into an issue where I was not able to use the Localization update module in Drupal on an Acquia hosted site. This is because the default location where the module stores translation files, sites/all/translations could not be created due to this directory being write protected. I suppse write protecting any directory location that could contain executable code is a good practice.
So where do I store translation files for sites on the Acquia platform? The idea of committing them to version control made me gag, so instea, I changed the location of this directory to be a place where the webserver could write, sites/default/files/translations, This setting can be changed in the Localization update settings page admin/config/regional/language/update.
If anyone has a better practice on this, please tweet it at me @johnbburg.