As many of you know, their is a common 1.3 SMP glitch, pistons may stop working, and if broken, may turn into invisible, unbreakable blocks. I have nicknamed it Block X. I have done some tests on it, as to attempt to discover how it behaves, is of any value, and most importantly, if they can be gotten rid of. However, feel free to make your own tests, and we can also discuss things about it here.-See through, besides the edges telling you what your cursor is over.-It is indestructible.-When hit, it makes the flakes of stone blocks, one of which is the piston.-Light blocks may travel through it.- A player walking into causes them to be unable to move from the spot.- Block may be placed on it.- Can glitch into other blocks, make them occupy partway inside of an existing block.- Water treats it as a solid block, unable to pass through it.- When hit, the flags system does not say you do not have build perms.- Lava treats it as a solid block.- Mobs cannot move inside them, but they do not appear glitched- Redstone cannot be pleaced on top of it- It cannot be powered to do anything- Sand falls through it, then pops back up to the top of the block- You cannot light them on fire, though for a little bit, the light comes up, but not the animation.- Sometimes, if shot with an arrow, the arrow will fly through.- Torches may not be placed on it.-Another piston will not push or pull it-When the block is changed into Block X, that blocks it would have pushed disappear.- Are mainly created when broken pistons, E.G one thats do not work, are hit or broken.Sorry for the dark text, but I copyed and pasted it. Anyway, I still need so meone to test if it may be blown up with TNT. Now, CONVERSE!Now, I have in fact found a way to fix it. If you have NO powered blocks around it, eventaully they likely will revert. This process can take a day, or it could take two weeks. However, do not reuse these pistons until they are fixed. Simply break them, which has a small chance of truning into Block X, or leave them there, so at least they are not glitched. If you have working pistons, remove their redstone, and any blocks they are touching. Then, if you wish to take the risk, break them.