I really haven't had any problems until last night. When war was declared on me, I ramped up research on a few techs to get some of the fighters I had designed in previous games. Once they were available, I bought one and hit the turn button. This seemed to put the game into an endless loop that it never recovered from. I repeated this a number of times with different ships. Once I was able to design a new ship using a custom base design and save it over another ship using the same name and it worked, but only once. Sometimes I could CTRL-ALT-DEL out of the game and kill it, sometimes I could only restart the machine. I also noticed that, in the designer, if I deleted an item, the numbers for available space would go crazy - like 212324324234 / 42342342348908 (not exact).