I'm working with a redstone portcullis which I finished in a sandbox map and exported to my build map.

Somehow during the export, though, the delay extender (necessary to turn an instantaneous pulse into a longer signal so the pistons & gravel have time to do their thing) was broken and instead of lengthening the signal, it just outputs the same flicker that it received as input.

I don't think it's an issue with the map itself, since I moved a few feet away and constructed a fully functional, identical delay extender just fine. But at the same time I'm not aware of any block entities that MCEdit wouldn't have been able to copy over, and indeed the build version is constructed *exactly* the same as the sandbox one as far as I can tell; I even rebuilt parts of it and have sent several different signal types through it just in case.

Any ideas what could have happened? Or better yet, a solution?