Dears, I am using gretl 1.9.5 running on Ubuntu 10.10. Here is the problem. It is probably a bug. I don't know. 1) I open a dataset, manipulate it and create some matrices; 2) I open another dataset and with the option --preserve I manage to maintain the matrices created during the session. And indeed I can see the old matrices with the new dataset. 3) I save the session and close the program; 4) When I reopen the saved session, in the icon window there is now none of the matrices I have created before, nor they can be called via the command line. It is strange cause the file size is actually bigger than before and indeed if I open the .gretl archive with an archive manager, I can see the data stored in the matrices in the xml file that is supposed to contain them. However, they disappear when I save the reopened session... Any suggestion? Giuseppe Vittucci