Forum:Help using the mako..

Ok, I am starting to feel stupid...I just started playing mass effect 1 and I'm using the mako on the on the UNC: Major Kyle assignment and I can't figure out how to continue the assignment. I'm on the planet right by the building and I have see the green colored entrance button interface but when I use the interact button(I have reconfigured to "x" key) it doesn't do anything. I've tried getting as close as possible, shooting it, waiting in front...almost everything I can think of but nothing happpens. Am I missing something or how do I interact or enter a building when using the mako? I would really appreciate any help, this is just frustrating the he** out of me...I feel stupid but no matter what I do nothing has any effect. I have the latest patch, running win 7 64bit, don't have any mods/cheats or dlcs installed. Thanks, -d.