I believe this issue is new to 1.8.1-pre3, although it might have been in an earlier pre-release build. It definitely wasn't in 1.8.0.
When we travel through a nether portal, either to the nether or returning to the overworld, our coordinates are off-set by 4-5 blocks in one direction. This can end up placing us inside blocks and causing damage.
I can provide screenshots later if needed, or any other information. It seemed to affect everyone who attempted it, and occurred on multiple portals in different locations.
Environment
SMP, Server on Linux, Clients on Windows and Linux
Dupe of MC-73504