Non-OP Adventure players can change spawner types, breaking pre-14w28 maps

CommandStats are not used when a command sign is right-clicked by non-OPs

Player skulls with SkullOwner do not use UUIDs; can break after name-changes

Scoreboard does not use UUIDs; scores will be lost by name changes

Cannot add or set scores of offline or "fake" players

"replace" directive in sounds.json does not work

Cannot hide potion effect tooltips using HideFlags

Cannot disable experience from villager trades

Slimes, Magma Cubes, Ocelots, and Iron Golems don't use generic.attackDamage Attribute

Resourcepack's glyph_sizes.bin and some unicode_pages are only loaded on startup

"/summon"ed or spawned LeashKnots always spawn at 0, 0, 0

Block Selection Cursor is No Longer Transparent

/setblock cannot set the orientation of chests, furnaces, dispensers, and droppers

Shader rendering takes priority over user input

Chatbar background doesn't show when typing.

Scoreboard does not display sidebar anymore

/give command creates crash-inducing items with incomplete [dataTag]

Painting / Item frame spawners crash the game, regardless of data provided

Hanging Entities (e.g. Item Frames, Paintings, and LeashKnots) cannot be spawned

Horse Spawners cannot have SpawnData or SpawnPotentials or they crash

Characters in Private Use Unicode Ranges do not render

Default vanilla font has certain broken characters when italic, such as /\()xkQ48%^

HD Compass PNG prevents Resource Pack from loading properly; results in a combined half-Default, half-custom resource pack

Status effects above Level 4 (such as Ench. Golden Apple Regenration) do not show their level

ALL Spawners with ActiveEffects crash the game, breaking hundreds of custom maps and servers.

Mob Spawners with ActiveEffects (Potion Effects on Mobs) crash the game

Thrown Eggs are no longer saved; deleted when world is reloaded

Mobs lose Attribute Modifiers when the player ventures too far from them

Command selector search radius offset by 0.5 in Y

Texture changing/reloading causes client-side freezing for 7-15 seconds

Jukeboxes stop playing after relogging/reloading world

Team colors/prefixes/suffixes are not displayed with @a/@p/@r

Team option "friendlyfire" is not saved to disk; resets upon map reload

Comparators cannot determine if a container is empty

Redstone Blocks do not act as a light source, despite providing power

Mobs cannot pick up items if mobGriefing is false, and custom spawners can't force them to

Armor enchantments (besides Thorns) have no effect on mobs

Water Breathing status does not work on squid

Players can place and remove arbitrary blocks in Adventure mode, breaking pre-1.4.2 maps

Lack of proper place to report annoyances in absence of the Wiki

Items at the top-left corner of a container cannot be duplicated with the pick block key

Villagers ignore data tags in trading

Positions of entities become offset to clients in SMP

Mobs can not be given more than five custom items

Dropped items with NBT tags do not stack