Minecraft – How to stop vines from spreading

Unless your minecart has a lot of momentum (not speed), powered off minetracks will stop your minecart. This wasn't the case.

The solution was placing powered minetracks right before, but I got the quantity wrong. Even with generous amounts of powered minetracks at launch, I needed four or five powered minetracks to barely offset a single powered off. That's perhaps because, since you stay on a powered off track for longer (you're slowing down after all), they cause more of an impact on your speed and momentum.

In my case five powered minetracks did the trick. Now the minecart walks those four pieces of track very slowly, giving passengers a chance to get their shot of nostalgia, and then picks back up the pace with more powered rail.

This approach isn't cheap, obviously, if you're not using /give or /i.

If the biomes shifted it's probably due to a corrupted "seed" (just a long number) which seems to happen quite easily when the server crash. If you have an old save that still is ok you can get the correct seed from that save, and then edit your current save and set the correct seed.

It's really easy to read and set seeds with LolEdit. You just open the save in the editor and modify the seed field.

If you have explored new areas while the seed was corrupted you might also get problems with "sliced walls". Check my slighty longish answer in this thread for a solution to that.