Because my system has been freezing ands crashing a bit recently, I have run TuffTest, DocMemory and Ontrack memory diagnoses, and the latter always seems to throw up errors whilst the TuffTest and DocMem don't. Obviously, the first two are DOS based utils, whilst the Ontrack runs in Windows, and this is the only real difference that I can see which might cause the discrepancy between the results. The question is, which test results should I believe, because it makes the difference between buying new memory or not?