I have been building a large digital clock in Minecraft and have noticed that sticky pistons have not been very sticky. To clarify, the display of the clock is controlled by sticky pistons that are supposed to both push and pull the blocks that make up the display which is usually comprised of white wool. However, the pistons have had problems pulling the blocks back after pushing them, leaving the blocks in the display when they should be pulled back to display the digits. I have tried replacing the pistons, making sure the redstone running to them was working fine, replacing the blocks the pistons were interacting with to cobblestone, and even tried reinstalling Minecraft; all to no avail. I do not know what to do to fix this, but the clock does not function do to this issue. To be clear, I have had this same issue on different computers and in multiple versions of Minecraft, including 1.3. Nothing has seemed to fix the issue and I would be grateful to anyone who could help me with this issue. I have included a link to some photos below to help show the issue I am experiencing.
I have already posted this topic in the support section and was advised that I should post it here as the fact that I have 3 pistons acting on a single redstone trigger, there may be some bugs associated with that. Anybody who has any ideas on improvements on design or what is causing the issue feel free to comment. Any and all comments/suggestions will be greatly appreciated.
The only problem with increasing the delay to the pistons is that that would throw off the whole timing. The purpose of only having one repeater on a one tick delay is so that the clock basically "ticks" at 1 second intervals. When counting like that, no issues occur, but when the display is advanced only one at a time manually (instead of automatically every second by the clock mechanism), this is where the errors occur. I would call this a bug in Bukkit, but I have had the same issue in single player mode as well. So, it is a Minecraft bug in general with sticky pistons. Apparently, after the 1.2 update, sticky pistons have been having issues with not being very sticky. I just don't know what else to do at this point other than give up on the project which I really do not want to do.
Thank you all for your help. Once increasing the delay on the repeaters to 2 ticks, the pistons worked fine. I also tried the redstone lamp theory as well, with mixed results. The biggest issue with the lamps is the crosstalk. So, a lamp diagonal to one lit up is also lit up due to this cross talk. I haven't totally given up on the lamps yet since it provides a truly "digital" display, so I will continue working on that. Thanks again to everyone who provided advice/suggestions.