salamano - is there a possibly another reason you can'get the upgrade? Do you have another upgrade of that type installed?
I'm pretty sure the game would tell me that I can't upgrade that element because I already have it installed (in fact, for each upgrade area, it would tell me what I already had there if I wanted to over-write it with a new one). But no, I don't have an upgrade of that type installed yet.
(This is at the Ruesland capital btw... where it's been getting pretty strange... There are upgrades disappearing and appearing there. Like, I haven't seen this upgrade since at that location-- and I still don't have it.)