Portal blocks (#90) not working properly

What I expected to happen was...:
I thought the normal entering a nether portal effects would occur.
What actually happened was...:
I was immediately tp'd to the nether and upon arrival the nausea effects began to happen, but I wasn't sent back to the real world.

Steps to Reproduce:
1. Type "/give (username) 90 1 2
2. Place the portal block
3. Walk into it and don't move