I'm having an issue where if I load any vessel that has ISA, about 3/4 of the time the game locks up completely (program bit responding) and I have to use the task manager to force quit. I'm running Windows 7, have the latest dev build of ISA for .20 installed along with the needy versions if mechjeb, lazer systems and remotetech. I did a fresh install of KSP, so I know there are no old plugins or parts installed.