Indeed! 
Made some empty tin cells and that was that, crafted no problem.
Played around with my Chrome extensions and found it was TACO blocking Real Networks. Unblocked; problem solved.
Thanks for your patience - I realize I seemed like a complete moron :p
No, did you see the screenshot? I'm using the exact same recipe as the wiki and no geothermal generator pops up. 
I know you're leery of people just not reading, but I use the wiki constantly. This one had me stumped and was unaddressed elsewhere.
Started a new game and this time I have a huge lava deposit right by me so I've decided to use a bunch of GeoGens but for some reason I can't craft them.
Screenshot:
I searched through the support forum and couldn't find anything on it - seemed like people are generally using them no problem.
I've got MC 1.8.1, IC2 1.23, BC 2.2.5 (all), RP 2 pr3 (no world or machines). I've generally had a bugless experience otherwise.
Any suggestions? Am I missing something truly obvious? I tried using a brand new generator as opposed to the one I had been powering with, and I even tried the old recipe.
Thanks 
