I can make iron tools on my Craftbukkit server with my account, but there are three other accounts that cannot.
This is an image from another player's account; notice no shovel appears:
Things I've tried without success:
- Stop/start server
- Reboot server
- Disable all Bukkit plugins
- Downgrade from the latest 1.6.4 developmental build to 1.6.2
- Make the player an "op"
- Have player login from my computer (and vice versa). I can create iron objects. He cannot.
On the same hosting service I launched a Vanilla 1.6.4 server, and that works: all accounts can create iron tools.