GTA San Andrea: Architectural Espionage, iPad?

GTA San Andrea: Architectural Espionage, problem. From the casino I start the mission, go to get the camera from the tourists, then head to the City Planning Department. I speak to the secretary lady, and after she tells me the plans are upstairs. The screen tells me the plans are located upstairs. However, the door I'm directed to go through, right next to the security guard that opens to the staircase, doesn't open for me. I've followed http://gta.wikia.com/Architectural_Espionage to a T. I can only assume I'm missing some game progress that won't allow me to progress further, but what? Thank you.