Had an alloy furnace yesterday, didn't work so I left it.
Updated today because you added alloy furnace logic, set it to make cupronickel, walked away.
Placed a macerator and the server crashed.

tl;dr placing an ic2 machine while the basic alloy furnace was working crashed server, unsure if it's a coincidence.

Here's a log
http://pastebin.com/sMnmER07

The alloy furnace crashes when it finishes processing everything that's in it. (It also doesn't use the items in the right slot.)

Thanks for braking everything while I'm away :) gonna leave a reminder to fix the input stack size checking here.