Thanks to all who replied to my posting about abnormally slow download speeds and frequent long pauses when using either gwdg or mathematik, and not being able to download anything because of "unknown signature" error messages. I have spent several (no, many) frustrating hours today trying to get apt/synaptic working properly. In spite of installing the rpmsig files following Richard's command line suggestion of using the --no-checksig --no-postinstall options, things got worse, with more and more problems occurring! I read all the archive postings on the subject as well. So I decided the only thing to try, was to "Do a Windows". I uninstalled them! Then I reinstalled them and installed the rpmsigs again, using Richard's suggestion. They are now working normally and I can download from the repositories with no problems. Thanks again for all the help. Cheers Keith