XML database fails to initialize


I’ve installed the XML Starter Kit on W2000 Professional running IIS 5.0. Everything seemed Ok, I was able to login, to define collections, import data and run queries. But, sometimes, I get this error: “XML initialization: registry retrieval failed for key”, MessageID:INOXHF8235. I mean sometimes, because I cannot reproduce the error.
Does anyone have any idea on what may be causing this error ?