[Closed] Pipes disappear
I finally set up some pipes below an automated wheat farm to gather all the items to one spot. They disappeared some time after a couple of days. None were next to chests. There were some extraction pipes, some iron pipes, and some plain transport pipes. All of them disappeared.
Obby mentioned his pipes disappear, too.
Note: the cause of this was discovered quite a while back. If anything (including other plugins) causes the Pipes plugin to not load on server start, all pipes in the world disappear since they don't have the plugin to support them. Then after the server is started with the Pipes plugin active, the previously existing pipes are no longer there, making it look like they randomly disappeared. It's up to the Pipes plugin developer to find a way to make them more stable.
As a result, expect your pipes to disappear while the server is in alpha and beta and we are still working out things with other plugins and server stability. I personally don't expect the Pipes plugin author to find a fix to make pipes persistent through a partly failed server boot.