Jedi Kerbal

I've had a MK-3 shuttle powered by 4 Whiplash Engines and 2 Tory Nuclear Ramjets to get to orbit and a Terrier and RCS for on-orbit maneuvering. With a little care it could make it to orbit carrying a half-full Rockomax 64 and have some delta-V left for other ops and then liquid fuel for a little atmospheric flying to land. A few days ago, I let CKAN update some mods. Since then, I can't get above 23k altitude and 11.5m/s, even empty. Thoughts? Thanks