So, I built a nice rocket. I took it into orbit around the Mun and brought it safely back to earth. I figured I was now ready to actually land on the Mun so I made a couple minor alterations to the rocket (basically added landing struts and an RCS). However, this new rocket swerved out of control on launch. I verified that all the new parts were symmetrical and to make a long story short I basically tried removing each new part one by one to see which was causing the stability problems. But even after removing all the new parts (so that it was exactly the same as the rocket that successfully made it to the Mun) it was still swerving out of control. I reloaded the original (good) rocket and again had successful launches every time. As a test, I removed a single part and then reattached it exactly as before and the rocket started swerving out of control again. So the exact same rocket which was working beautifully 1 minute earlier, suddenly stops working if I simply remove and reapply a part. From what I can tell, nothing has changed with the staging or symmetry. I\'m kind of lost right now. Has anyone else experienced this?