Help with access cctv dvr via phone

Help with access cctv dvr via phone

 

Hello,
Need help with connecting with cctv DVR via cell phone. I have a HTC Tilt phone with At&t 3g network. I am running windows moblie 6.1. and pocket cam program. I can connect to my Dvr system and view live image and control ptz cameras when I am on WiFi connection with the phone. If I try to connect without WiFi I get a blank screen. Does anyone have any thoughts??