Hello, I used to use those features in Silva. It work well with 0.4, but it's broken in 1.x. (I have tests in Silva testing that). This have to do with the wrapping (to remember the aquisition path) of an utility which is done inside the registry by registerUtility, which breaks the unregisterUtility. unregisterUtility is checking that the component you want to unregister is the same than the one which is in the registry, for the same specification, which is not true, because the one in the registry in wrapped with a ComponentPathWrapper (in register). If you do grep unregisterUtility in five.localsitemanager, you have no match, but the site API defines both, so they should both works (and so be tested). I volunteer myself to add test (and fix it) in the SVN, as I need that fix. Does anyone have an objection with that ? Does any official maintainer will do a release (1.1.1, as it will be a bug fix) afterwards ? (of course, the trunk will need to be fixed if the same problem is present, and no, I do not want to use the trunk, but the 1.x branch). Best regards, Sylvain Viollon -- Sylvain Viollon -- Infrae t +31 10 243 7051 -- http://infrae.com Hoevestraat 10 3033GC Rotterdam -- The Netherlands