This is indeed still a problem in 1.5.1. Please fix this!
The problem still exists in 1.5.
You are right, now it works for me again. I don't know what caused the problem in the first place, but when I tried again today on 13w10a, it was back to normal...
This is still a problem in snapshot 13w09c. Please fix this, because this is the one thing keeping my map from perfection. What I'm building is a PVP map where one can buy various items, and different item categories have different colors in the name (red=weapon,grey=armor etc.). You can also buy enchanted books, but when you use the anvil to upgrade your equipment the color is lost, changing "Blade of Evil's Bane" in red text to "4Blade of Evil's Bane" in white text. Very annoying.
There is definitely something not working about using @p in /scoreboard teams join. It works for me, but sometimes I have to activate the command block twice (though this might be an error in my redstone wirings). However, I can confirm it does NOT work if you add arguments after @p.
Confirmed for English(UK) as well.
I understand that you wouldn't be able to add item colour ingame, but it is really annoying that items lose their colours when you use an anvil. It would be good if the colour would just stay the same if you don't rename it, but change back to normal if you do. I am making a PVP map with these features, and it's not very nice to have "Master Sword" turned into "8Master Sword" with no colour.
Sure, the same thing happens with minecarts, but i would not view this as a duplicate of MC-1291. That report was about people turning invisible AFTER leaving the minecart. What I describe here is people lagging and disappear WHILE riding it. Clearly not the same thing, and therefore this should not be put down.
On another note, I did some more testing and it would seem that the place to where the player seems to "jump" is the place where he got in the boat/minecart. Might make this easier to solve.