I have recently installed a Drupal site on our web server and this is the default host (replaced an old website with static files). This server also hosts another virtual host for another domain name and that installation is WordPress.
On blog posts on the Drupal site (regular pages are fine), images will eventually show broken icons and when you check the URL of the image, it's replacing the domain name for the Drupal site with the domain name for the WordPress site.
Clearing the cache within Drupal immediately fixes everything, and the images reappear and with the correct URL.
An additional oddity is that the images are broken inside our network, but from the outside they will show up even though using the incorrect URL. On the inside, it resolves to the internal IP address and on the outside to the public.
I'm using Apache 2.2.22 with Drupal 7.28.
I realize it could be an Apache issue or DNS issue, but I'm checking all avenues... is there a configuration for the Drupal cache that I should be taking a look at that could be causing this problem?