Arkham City. Stuck early on (slight spoilers from the first hour of the game)

So either I've found a completely new bug in this game or there is something seriously obvious that I am overlooking.

I'm just going to see mr. Freeze for the first time and I'm at the GPCD building.

I have seen online video walkthroughs that you are *supposed* to shoot at the electrical engine thingie above the vehicle entry hatch and then glide under the doorway, but when I fire my EMP onto the engine, it starts running but the door doesnt move an inch!

I have been unable to find any reason as to why this is happening. There doesnt seem to be any buttons I need to push, and I've even cleared out all the enemies around the building.

I've tried standing right next to the door and starting the engine and standing far away. No reaction.

Am I doing something wrong here?!

Make sure you're using the right charge when using the gun. There's a charge for pushing objects away and for retracting them.

Of course!

I knew it was probably me being an idiot.

Thanks a lot. Now I can get on with my Batman fueled adventures!