I upgraded from Office 11 to X4 approx. 3 months ago. It keeps crashing for no reason at all. I have the auto save set for one minute so I do not lose much information. I contacted tech support and did what they told me to do. I was told to contact the store I purchased it through if I continue to have issues. I installed SP1 and it is doing the same thing. It is annoying as hell! I cannot return it because it is three months old. Is anyone having an issue like this? I suppose I will have to live with it. I do not know???!!!