The freeze or near freeze seems to occur when KM has the whole window. I did some testing with the new 1.5a and what I found was that when KM' screen was about 80% of full screen it used 53 of CPU and I could control the menu OK. when I clicked the window size icon (the middle one) then CPU slowly went up to 99 and the screen appeared to freeze. I think it became very, very slow. Sometimes I could click on the red X and it would close in 90 seconds. Other times I had to end the process to get out.