Bug report:

MineCraft Version: 1.6.4
Forge Version: 9.11.1.965
Mod Version: 2.1.0

Other relevant mods:
Gravestone 2.4.7

Bug Description: Dying while GraveStone is installed causes invulnerability

How to reproduce the bug:

1. Install Sync and GraveStone
2. Construct a shell
3. Kill yourself
4. Your shell will activate, then die in the same place that you died. You your shell will respawn AGAIN, and will be completely invulnerable (can't even use the /kill comand). Also, the shell storage will remain closed for some reason.

Seems to be fixed with 2770aa4 as cannot replicate now.

A similar bug occurs with OpenBlocks graves. If you die, you transfer to a shell correctly, but the shell is completely invulnerable.

EDIT: During further testing, I also saw OpenBlocks have the same problem as with Gravestone. (Shell dies, transfer to new shell, new shell immediately dies in the same spot, next body is invulnerable.)

EDIT: Invulnerability carries over to all other shells. Exiting the map and re-entering doesn't fix the problem, nor does restarting MineCraft. Shells created afterwards are vulnerable, but all existing shells seem to be unkillable.