Dear Andreas, it was fun reading your blog post: http://boinkor.net/archives/2011/10/a-weird-problem-with-asdf-on-nfs.html You're not the first one having experienced problems with clock skew. In 2.011.3, we fixed an indefinite loop that could happen in defsystem in presence of NFS clock skew. Instead of merely a workaround, what about a real fix? Can you tell me how ASDF 2.017.9 works for you? At some point next month it would be nice if Allegro would upgrade to ASDF 2.018... —♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org