In your documentation, you say :
Go to plugins/system/gtranslate/gtranslate (or /plugins/system/gtranslate for joomla 1.5.x versions) directory and set /gtranslate/cache and /gtranslate/cache/XX folders permissions to 777. DON'T change other files/folders permissions.
But you don't say if subdirectories must have also permissions to 777.
Because it is very slow when I select a language, and you say it can be a problem with permission.
But you don't say in your guide if we have to put 777 to cache and cache/folders