Problem with parts

[cwmonkey]

From issue #6:

Also I had a situation when I was digging some EP's via Particle Accelerator - rather basic build:
HEAT WENT
HEAT EXCH
PART ACLT
DUAL DOLOR CELL

Setup whole row of these (with one tile space between each "EP column"). And it worked fine. Expanded one row. Added missing parts (with nuclear cell in the end) and it went KA-BOOM (as stated in particle acc description). Can't reconstrunct right now but I will try to do it again.