mac os x 1.6.0_65
What I expected to happen was...:
The sticky piston should of made sticky piston particles.
What actually happened was...:
When I broke the sticky piston that was connected to the redstone it made lava particles.
Steps to Reproduce:
1. first connect the sticky piston to active redstone
2. ...then break the sticky piston
3. ...then it makes lava particles