Very cool - have you taken a look at Geoff's Climate Cookbook? Very indepth doc about figuring out climate areas and such, and it starts with figuring out the tropical and polar areas. I can image a lot of whirlpools/maelstroms in that large sea in the west - or at the very least a very strong current (similar to the one in the Atlantic) that sweeps ships around; could be hard to get out of such a strong current if the technology level isn't all that high, which could explain an unknown continent/landmass in the middle.
The shapes of the landmasses are great, and that big landlocked (? almost?) sea in the north of the eastern continent could potentially help create a really interesting climate up there - the water will cool the air and surrounding area, but the "horizontal" (like Europe/Asia, where the Americas are more vertical) nature of the continent seriously inhibits the progress of any storms, so there could be room for a dry, cold 'desert' area up there.
Sorry! Just thinking aloud; you've got a great base to work from here! Looking forward to seeing more.
P.S. as for G.Projector - maybe compatibility mode, or run as admin? Download the newest version from NASA (if you don't already have it)? Otherwise, I could run it through for you, as I've got G.Projector and (so far) it's working.