Is that reproducible on server/client setups or did you just see it once? Main reason to ask this is that I really just copied the vanilla code to put items into the production queue, which seems to be the only issue you are reporting (that it got lost once you queued it). I'll probably check it at some point, but if you can say it is always happening, I'd consider it a bug in my mod, otherwise, it could have any reason that may also happen in vanilla.