According to Mojang press-release, Minecraft ver1.5 will appear in early this month.
Many new features such as nether-quarts, hopper&dropper, and redstone block are expected to implement.
Especially hopper and dropper, there are some reports that automatic mob tower will be available.
That kind of mob tower will cause serious heavy load on server and network connection.
To reduce the expected lag, Admin&Mod team decided to stop spawning from all mob spawner in main world.
Also any kind of requests related to mob spawner will canceled after 3/4(JST).
We are now looking for alternative solution for this issue. Please wait for following announcement.