Update: Nevermind, they are just rather slow to attack. Confirmed fixed.
I updated to 1.6.1 (PE), problem seems to persist. They do fly farther down/closer, but won't actually come within 20 blocks or attack, at least for me.
Just happened to me again. I have noticed a trend that it literally vaporizes armor, unless either the armor is leggings or Projectile Protection (both times that was the only armor piece that survived, helm, chest, and boots had vanished). I would theorize that a calculation error causes a fireball to do infinite damage, meaning armor with regular, Blast, and Fire Protection gets destroyed, and the player automatically dies.
Also noticed this. You can't interact with items or mobs in at least some cases, definitely needs fixing.
Also reported this, can confirm. It seems to be able to happen to any particle created, but higher groups (e.g. dragon's breath, bubbles, nether portals) have higher possibilities of it happening.
Advice: get a Power 5 bow before going to the Nether like I did, one shots everything. Aside from that, blazes are supposed to be tough. Your comment is akin to saying, "I know the Ender Dragon is a boss, but it isn't supposed to be THAT hard!" Uh, yes it is. Just because you find the Nether hard to fight in doesn't mean you can come rant about a "bug" that really just amounts to you being bad or inexperienced at the game. If you keep spamming, I am sure the mods will ban you, as well.
Well, they won't reply instantly, be patient. I do know a temporary fix: factory resetting the device fixes it, although you obviously lose all data. Have had to do this twice, but hasn't bothered me for a long time.
Still occurs in 1.8.0, even with the new texture pack beta (jungles legitimately look like vomit now).