Two issues; strange ID conflicts and Redstone tab crash

[Gerhard]

so, first problem. I assemble my modpack on my computer and it runs fine. No conflicts, nothing. I add my configs to a server and I can connect to it just fine, without issue as well. When I bundle my configs into my modpack and have my friends download it, they get ID conflicts and some of their config files are entirely blank (such as in the case of Gregtech's configuration files). So these files are being overwritten or deleted even though they work fine on my PC. I'm not sure why this is happening.

Second of all, I get a crash pertaining to some sort of item render issue on a certain page of NEI and whenever I click on the "Redstone" tab in Creative Mode. I don't know why this is happening and I can't figure out what mod adds the offending item. If I scroll down the Redstone tab in the NEI Creative Tabs section, one by one, its whatever item comes directly after the Comparator.

Is there a way I can figure out what item that's supposed to be so I know what mod breaks it?

[31trainman]

remove mods one by one and try.