Changes do not take effect

Hello. I am using wordpress 3.5.1 and recently switched from the tantan-s3 to this plugin. Now it seems that the configuration changes that I make have no affect in this plugin. I deactivated and removed the tantan plugin.

I am trying to turn off virtual hosting. The box is unchecked, but when I check my site with old or even newly uploaded images, they still come from the virtual hosting domain.

Where is the config file located (or where in the DB) so I can change these manually and see if there is a permissions issue or something else going on.

https://www.ads-software.com/extend/plugins/amazon-s3-and-cloudfront/