[1.6.4] Multipart blocks being deleted on carriage move

[SegFault22]

I have created a carriage-based mining machine, which uses Advanced Repulsion Systems plate forcefield projector with block cutter upgrade to remove a plate of blocks, collects the items with powered Buildcraft obsidian transport pipes, then advances itself forward and repeat. However there exists a problem where multipart blocks (such as Thermal Expansion conduits/itemducts, microblock covers, and Project Red wires and logic gates) are occasionally destroyed when the carriage moves. They are not dropping any items, they are simply deleted. Since I have to use TE conduits to sufficiently power obsidian transport pipes, and itemducts to efficiently move collected ores and cobblestone, this issue is extremely bothersome - especially considering that there is no evidence of the problem occurring, except the spot where the conduits/covers are missing from

Before the bug happens:

Missing conduits:

(I removed the energy cells, in trying to remodel it to use non-multipart EnderIO conduits for feeding the obsidian transport pipes, but that does not work)

I can not update past 1.6.4, because I am using mods that require world reset in order to work with any version past 1.6.4