The mentioned problem isn't due to plugin code, but it's a geometrical problem. It's very difficult for me (specially for my English) to show the reason of that (if you want I can try but...).
The A,W,S and D keys are used for setting the camera parameters, this is an old Rui's request (whatever you get, whatever you set), and not for other purpose.
However, now I'll try to prevent that nasty geometrical situation.
Thank you very much.