Piston will not extend when placed on packed ice.

I was creating a redstone build and then the pistons wouldn't extend. Tried from various sides and the piston still wouldn't move. I do consider myself a redstone builder, so I was very confused at first. I was playing on the beta, so it might just be that. I don't know if this can be reproduced or not, but try powering a piston over ice, just to check. I was at -43, 67, -249 if you want the coords. That's where the piston was.

Steps to Reproduce:

1. Place piston on packed ice
2. Put a block in front of the piston
3. Start redstone

Observed Results:

Piston does not extend when powered by redstone

Expected Results:

Piston works as normal

No image available.