Step 15 stopage

At step 15, I get the following error:

    Matrix system not successfully loaded, you will have to delete and reinstall MySource Matrix. Currently using session from installer.

The version of php installed on my server is a CLI installation and open_basedir is off (as is safe mode). I'm quite baffled. Anything else I should check? If I try and jump to the /_admin, I get a 403 (forbidden) error.



(mysql is 4.0, all pear modules are installed,)



Other question: In step 3, there is a reference to the "System Root". I assume this is where I've extracted the mysource_matrix_3-2-1.tar.gz file.



In step 5, we are asked for teh "Site root URL". In this do I put the URL of the page that I want to point to the "core files"? (ie: the website is sub.domain.com, but the core files are in sub.domain.com/sys/) Which do I put?



Finally, in step 8 when trying to create symlinks, you are asked for the "Directory to symbolically link as MySource Matrix web root". Which is this? The public URL or the directory of the matrix installation. Further, is this supposed to be a relative path, full system path, or the webpath (ie: sub.domain.com/sys).



Thanks.