Board Thread:Questions and Answers/@comment-72.152.35.74-20130205073504/@comment-5665892-20130209032417

It's a known bug with Tekkit 3.1.3, there is also a bug with the Advanced Machines IC2 addon.

As of now there is no fix that allows you to keep all the mods, but you can downgrade to 3.1.2 and try to solve the problem you had in it.

If you don't have any Railcraft (You deleted the jar, so you don't) and turtles from CC you won't have any problems downgrading.