Refresh the repos, and try again. I had a typo in package control file which may be what prevents sliderotate from installing correctly. If necessary, uninstall sliderotate first, then do the SSU to 4.2008.36-5, then install sliderotate again. Check that the version is 4.2008.36-5.28 not 4-2008.36-5.28 (the broken one) If you see the one with the dash, update the repos again. sliderotate-4.2008.36-5.28 should install quite cleanly.