Remine Repository Statistics Page does not display graphics when accessed using the virtual server URL

I have Redmine setup on a virtual server. When a user clicks on the Statistics link from the Repository tab, the page populates with 2 missing image icons and the back link. It took me awhile to identify the issue is related to the URL.

I have a second instance of Redmine installed on my local machine to test plugins / changes before I perform a change to the company Redmine site on the VM. Both are Bitnami stack installs with:

Redmine version 3.0.3.stable
Ruby version 2.0.0-p645 (2015-04-13) [i386-mingw32]
Rails version 4.2.1
Database adapter Mysql2
Subversion 1.9.2

I did the following to isolate the circumstances in which this happens:

• Accessed Redmine using the address http://localhost/redmine/ from my local machine and WAS able to see the stat graphics on the Repository Statistics page
• Accessed Redmine using the address http://machine_name/redmine/ from my local machine and was NOT able to see the stat graphics on the Repository Statistics page
• Accessed Redmine using the address http://localhost/redmine/ in a remote session on the virtual server and WAS able to see the stat graphics on the Repository Statistics page
• Accessed Redmine using the address http://server_name/redmine/ in a remote session on the virtual server and was NOT able to see the stat graphics on the Repository Statistics page

I have searched for a resolution, looked through config files hoping to find a setting I can alter or append. Can someone please assist me with instructions to correct my issue? I want users to be able to properly view the Repository Statistics page using the virtual server address.

Thanks,