Problem with frontpage redirection

Hi,

We are using a production environment i.e under domain.com (here is WP Super Cache installed) and staging under dev.domain.com, we are not sure how is it possible that our production website was redirected to staging..

We’ve checked .htaccess file, plugins settings – no redirections there, only wp-cache flush (via ssh) helped.

How is it possible that the staging domain was cached on the production?

Thanks,
Piotr