Are anvils supposed to NOT work for normal users?

Hi. A lot of players on my server are complaining about that the anvils are not working for them. Whenever they try to anvil their sword for instance, combinated with an enchanted book, it would just simply not work but their XP would be removed leaving them sad and wondering what happened..

The anvils are working just fine for me (as an OP) but as I wrote not for the normal users.

I am using Essentials as one of the core plugins, could this be the problem?

If not, am I doing something wrong? Are there any permissionsI have missed?

 

*push* ... same problem...

 

After reading minecraftwiki.net (the talk section) I found out:

When you try to repair items while using another language than English, it might fail.

The reason seems to be the fact, that the name field is filled with the localised name, while the server still thinks the item has it's english name.
-> the client thinks it doesn't rename, while the server says it does rename
-> the action is much more expensive than shown for the player
-> it will fail if the player has not enough EXP

Also I think this error may also occur when the client is using mods.

However, it's a Minecraft Bug which also occurs in the lastest snapshot.

Edit: https://mojang.atlassian.net/browse/MC-1907