I'm not saying that SED is a bad program. As I said before, I like SED, primarily for its simplicity. Every game engine has its limitations, or disadvantages, which are made up for by expert programmers. I was just expressing what I experienced just in case there were due to bugs in the program. However, as you suggested, I will check if the problem is with my computer. Perhaps it needs 1 GB or ram, instead of 512.