It also works with arrows and dropped items.
Also works for shooting arrows out of the world.
Update: bug works not just vertically. It works for a 27 block radius in any direction.
You shoot the arrow while above build height.
You must be in 3rd person mode for these to occur
Whoops...
Sorry...
Accidentally submitted before I was done.
Basically you go into third person and fly above build height.
The arrow part is self-explanatory.
Theoretically, yes, but people have been asking for that for a LONG time.
Your problem is a similar one to mine. I already had a Mojang account and logged in, and nothing happened.
I saw this:
Is Modded: Very likely; Jar signature invalidated.
To delete mods, clear your bin folder. The client will make a new bin.
You modded your game. Don't whine to Mojang about your wrongdoing.
This is intended.
If you saw a video made by SethBling, you will find out that pistons constantly check their state, but will only react to a powered block if they are more than one block away.
This is an intended feature of dispensers and droppers.
When they receive a redstone update, as comparators do constantly, the dispenser or dropper will fire repeatedly.
Don't post these things where BUGS are posted. You're wasting the devs' valuable time while they could be looking for bugs to fix.