When you try to chisel a block of lead/copper/bronze/etc., that has a block equivalent in IC2, for some reason the game crashes. If you chisel the thermal exmansion block placed in the world - u get only the IC2 varian. U can never get to "Shipping Crate" or "Caution" variants of lead blocks for example. Any idea how this can be fixed?

Maybe it would help if you gave the crash report? "It crashes" is not helpful to debug

It was the oredict problem. Everything works fine now.