I has playing in minecraft pre-release 1.4.2 and i found a bug with sticky pistons and im not sure for regular pistons as well
Linked issues
duplicates 1
Attachments
Comments 2
Duplicate of MC-136
MC-339
Bugs in 1.4.2
Resolved
Duplicate
0
You are going to need to provide a bit more information about what exactly is happening and what steps can be taken to reproduce the problem. This will help tremendously in fixing any bugs.