Thank you for the advice on dealing with the undefined symbol in Ubuntu and the pointer to the discussion of Atlas, etc. I will experiment with alternative versions to the libraries to see what works best. On the first point, I have identified that the following types of file can't be located with the default installation: (a) help files (this warning comes up when the program loads), (b) gretl logo in Help/About dialogue, (c) sample data files (File/Open data/Sample file) and database (File/Databases/Gretl native), and (d) sample script files (File/Script files/Practice file). I think that there are others, but the key seems to be the location of ./data, ./db, ./demo (probably), ./doc, ./scripts. I haven't experimented with plugins but those may go in the wrong place too. You may be correct about the default setup for paths under Ubuntu & OpenSUSE - again I will experiment with alternative setups. Sven's option works - provided that you have a Tex processor installed, which I didn't initially - but only with respect to help files because it forces a rebuild of the documentation. The data & script files are still put in /usr/share Gordon Hughes On Mon, 23 Jun 2008, Gordon Hughes wrote: Which files get lost in this way? Jack has responded to this one. I'll just add that it seems to me to be a slight glitch in the Ubuntu packaging system. The package containing liblapack.so.3gf should really have a dependency on the gfortran package, but it doesn't. You won't hit this issue if you use the "vanilla" lapack package, but if you're using the "gf" atlas lapack, uninstall g77 and install gfortran. You might also take a look at: <http://www.ecn.wfu.edu/%7Ecottrell/tmp/gretl_speed.html>http://www.ecn... Allin Cottrell