VPN Client Routing

Greetings all, i am a network/systems administrator for a multimedia company. we have over 800 clients we support. our setup is easy, i have a content server at every site, and we connect to them via a windows server vpn client. some of my sites, i have other network devices that i need to access from home base that are on the same subnet as the vpn client’s ip. no matter what i can always see the server from home base, some sites i can see the other devices, other stores i can. all my sites connect through 1 of 2 cisco 2900 routers. can anyone lead me i the right direction to pinpoint the problem? thanks.