fixed bug with covariates

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/basta@800 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
minor edits.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/basta@801 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
minor edits.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/basta@802 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
minor edits.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/basta@803 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
fixed bug with covariates

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/basta@804 edb9625f-4e0d-4859-8d74-9fd3b1da38cb