I hope this hasn't been reported yet, I have found a dupe bug with routing table copy-crafting mekanism.

Desc:
I have ~9 brand new, clean tables and 2 written ones, I place them in crafting grid like so: on top 2 written ones, on bottom 9 empty ones.

From crafting I should receive 11 tables, instead I receive 11 written one and 8 empty ones still remain in grid, basicly adding 2 written ones to any number of empty ones doesn't clear the whole grid :)

The modpack is ResonantRise@Atlaucher, the Railcraft version is Railcraft_1.6.4-8.3.0.0
If you need any more details tell me ^^

PS. Just started a railway system and loving every bit of it, railcraft is awesome :)

K, will fix.