Hmm, they built for 1 turn without any road showing, and on the second tile they stopped building.
Wait! Let me check if perhaps kyrub fixed the road exploit in insecticide 1.40n.
I'll retry in vanilla.
EDIT: Yep. Now it works without a glitch. Just ending the turn on arcanus seemed to do the job.
Hmm. I guess I just verified kyrub did a really good job.
Pity though for my scenario.
Wait! Let me check if perhaps kyrub fixed the road exploit in insecticide 1.40n.
I'll retry in vanilla.
EDIT: Yep. Now it works without a glitch. Just ending the turn on arcanus seemed to do the job.
Hmm. I guess I just verified kyrub did a really good job.

Pity though for my scenario.
--I like ILSe