I am using 32bit ksp with quite a few mods (enough to require using texture reduction in order to get ksp 32bit to load) and I had lots of trouble with crashing during scene changes, often accompanied by a log dump showing "Write to location 00800000 caused an access violation" I would usually crash every third or fourth scene change.... (to vessel, to vab, to lauchpad, to space center.......) I launch KSP using a desktop shortcut to a .bat file which then launches ksp.exe with a high process priority (not 100% sure if this gives physics calculations a boost or not) start "Kerbal Space Program" /high "I:\Kerbal Space Program\KSP.exe" I added "-force-opengl" to my target line in the shortcut and so far, I have not had a scene change crash for more than 8 scene changes my memory usage for KSP and forcing open GL is currently 3.4GB according to the Resource Monitor, you can find this handy tool on Win 7 Pro x64 by ctrl+alt+del, selecting the task manager, clicking the "Performance" tab, and clicking the button near the bottom "Resource Monitor" The memory tab shows the working set in use by each process. Vessel switching seems to be much faster and i managed about 10 vessel switches before a bug forced me to restart ksp (bug locked me to my current vessel, i could to go to space center, switch vessels, or quickload. But I was able to quicksave....) BUUUUTTTT 10 vessel switches is 2-3 times more than usual before a scene change crash, and I have seen the vessel locking bug before... maybe that one is due to one of the mods......