Windows - Java 7

Your code is very complicated.
You need to make it so that it is the simplest code which causes the issue.

Give him a plugin JAR to test with. Code takes time to compile, and time is one thing that md_5 is short of.

If it doesn't work change the 10 for 20 or so.

Try this in a superflat world:
http://pastebin.com/tcrFMyTh

Maybe include a plugin which can reproduce this issue?

If we can actually test an issue without putting in lots of legwork it is more likely to be fixed.

I'm using a repeating task that works every 1/4 seconds, so that's fast. I'm not teleporting it far, every teleport it only moves the entity 0.1 to 0.3.

Can you be more specific? How many times is a lot? How far are you teleporting the entity? If you're teleporting them with a plugin, what exactly are you doing in the plugin?

Definitely confirming this as a bug.

If you teleport an entity a lot, and do it multiple times, it is possible to cause this bug. I'm unsure quite what causes it (could unloading chunks be part of the issue?), but it definitely is to do with teleporting an entity multiple times.

I most often see this issue on public servers. Personally I've never replicated it on a private test server with only one player online, but have replicated it on my public server and another public server in the past.

The bug happens in both 1.7 and 1.8.

Your build is not the latest and therefore may be the reason you are having this issue. Spigot is 24 version(s) behind. CraftBukkit is 2965 version(s) behind. This message was automatically generated and is not guaranteed to be a solution to your issue.