The OP only 33x33 radius around spawn does not work.
Any player can destrow the spawn.
Linked issues
is duplicated by 6
Comments 3
Have tested on new 1.4.2 vanilla server. Ensure ops.txt has at least one entry and then spawn-protection should work fine.
https://twitter.com/Dinnerbone/status/253986918897942528
Tested and confirmed.
Vanilla 1.4.2 SMP server has no spawn protection.