Water bug

When making a cobble generator the water is not behaving the way it normally does.

The water was flowing a little too fast or something so the lava would eventually turn into obsidian, or they would never make anything.

Steps to Reproduce:
1. put a flowing block of lava in a channel 6 blocks away from a water block
2. let them flow
3. they should just stop and not produce cobblestone

Not sure if this is a bug but I found out about it when playing with my friends.-
MangoMadness20