Issues with a Portal Gun

Greetings all,

I was following this Portal Gun tutorial series:

I've followed it from beginning to end and, as far as I'm aware, have followed it precisely. However, when I fire my projectile, the portal appears immediately in front of me, rather than travelling as the projectile would, as seen in the final video of the above linked series (6:03 onwards). Also, when my projectile fires, the default projectile within the FPS template continues after the portal has spawned, rather than being destroyed and replaced by the Portal spawning. Also, I'm able to spawn multiple entrance and exit portals in succession. Each use of one of the portals is supposed to remove the previous one - meaning there should only ever be one of each.

Does anyone have any idea as to what could be causing these issues? I will make and provide screenshots if need be.