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Dear SPM-list, I am having some problems when trying to reanalyze old data with spm2: two-sample t-tests between two groups suddenly seem to produce only empty spmT images (the whole spmT_000x image is 0). I've been using spm2 for years and have never encountered this problem. 1) This problem is specific to two-sample t-tests between the 2 groups; one-sample t-tests in spm2 on each of the 2 groups work fine and produce the same results they did a year ago. 2) This problem is also specific to spm2; the same two-sample t-test between the 2 groups using spm5 works fine and produces the same results as I got a year ago with spm2. 3) 2-group ANOVA in spm2 (should produce the same results as 2-sample t-test) again only produces empty spmT images. 4) I have re-downloaded and installed spm2 and tried the two-sample t-test on both Matlab6.5 and Matlab7.1. All to no avail. 5) The 2-sample t-test design matrix from the current analysis looks radically different from the design matrix from the analysis I performed a year ago and I do not seem to be able to reproduce the design matrix from a year ago in spm2 anymore (I tried every combination of the 2-sample t-test settings possible). However, as mentioned above, if I do the same 2-sample t-test in spm5, I obtain the same results as I did a year ago again, therefore I feel confident that my 'old' results are valid. I am pretty much at my wits end as to why I no longer can perform 2-sample t-tests in spm2. I would really like to stick with spm2 for this old dataset (am just trying to do a few small additional analyses in response to reviewer's comments). Does anybody have any idea what might be going on here and how to solve this? Many thanks in advance, Bianca de Haan