Mac OS X 10.8.2 Mountain Lion, Java Supplied on OS X.
Specs of fireworks disappeared when stacked, even worse the server crashed when I tried to use the firework which I configured to my liking it crashed causing a recurring end of stream.
I expected minecraft to remember the data on the fireworks. And light them accordingly.
But what happened was it forgot, booted everyone off the server and stopped us from entering.
This may be a Anomaly in the code but this is what I did
1. Created four fireworks.
2. Put them into a stack.
3. Spread out fireworks in to last four boxes.
4. It should have no Specs.
5. Fire them.
6. Servers running just not letting you on.