Whenever i go to the nether i'm getting stuck in the bottom portal block for some reason. It also occurs if you travel to the overworld. In 1.3 you used to fall through the bottom block of the portal sometimes.

What I expected to happen was...:
I was expecting to go safely to the nether.

What actually happened was...:
I got stuck in a portal block and i take lava damage when theres lava next to the portal.

Steps to Reproduce:
1. Host a server (i used a dev build of craft bukkit which might be the problem)
2. Enter the nether

I've had a few players on my server complaining about it while other players couldnt reproduce the problem.

I hope this helps!