A warning to all Wither hunters.

Blaze spawners don't care about light level, They spawn in direct sunlight I believe.

Then how does Etho's lava disable mechanism work?

It doesn't, Or shouldn't do.

http://www.minecraftwiki.net/wiki/Blaze#Spawning
They spawn in places 11 and below. Which is pretty bright (i have no clue what the max light level is...).

A light level of 11 or less so say the wiki.

I seem to remember I covered the whole thing in lava once and they kept spawning, Strange they must have changed it.

15

Spawners spawn area is upto 4 blocks from spawner (I think). Lava has light level 15 so if a spawning space is more than 3 blocks from lava a blaze could spawn. Lava dumped ontop of a spawner is not enough (just) as the corners of the spawn area will be at light level 11.

Its not just spawners, random spawning blazes are the real issue.

ok so later tonight withers skels are going to spawn in every fortress even ones that were generated in 1.3 and back?

They already do, Just got my second skull

The updates done.

hell year!!!!!!!

Hey if you spawn withers in water they do no damage