entering nether with connection lost leaves one ... lost, portal-less

The first time this happened, I was entering for the first time. in medias res, I got a connection timeout. Fine. I re-connected to my server. All well and good. But I am in the nether and there is no portal anywhere around. I had to get back by jumping into lava.

This time, I had landmarks available, so I found myself. But it does seem to be reproducible.

Any ideas?