This is what I did (using newest version):
1. Got L5 card
2. Disabled remote control doors
3. Talked to 079
4. Stayed till he said "ok you die now"
5. Went back to Gate A
6. Door still wont open!!!

Please help me!
It's my first time playing to and I didn't cheat.

After talking to 079 you should re-enable the remote door control system before going to Gate A or Gate B.