From the main MechJeb thread: This is happening to me frequently since installing the testbed patch/new AR202 cfg, but never before. Even with the root part oriented correctly and the navball pointing the right way, every rocket tries to tip over almost immediately after launch, and always in the direction which would place a radially mounted AR202 "right side up." I think it's only happening with new/modified designs but I haven't done enough launches of pre-patch designs to say for sure. As it says in the quote, if I close KSP, delete the .cfg file, and start it up again it seems to "fix it" but anyone with more than a few mods and more than a couple flights in the air at a time knows this is a tedious process.