I am having the same exact problem. Vegas has froze almost every time I open it. After every 20 times or so it finally opens and I try to render my project but it says system low on memory and sometimes just gives me an error. It was working fine until just recently. I do notice that the FileISOsurrogate.exe proccess is using a tremendous amount of memory, even more than I think it should, and it keeps getting higher. Have you found a solution yet?