incorrect portal transfer to nether

Put the summary of the bug you're having here

What I expected to happen was...:
Enter at my nether portal in overworld in coordinates 150 68 242. I must travel to my portal in nether at 19 119 31. I made this trip many times

What actually happened was...:
I arrived at the coordinates (in the nether) 150 68 242 (same coordinates as the overworld). No portal, I'm buried in nether rack

Steps to Reproduce:
1I can't upload the game, has 69 MB. I uypload the level.dat, i don´t know it is useful
2.
3. ...