I had a DSN that, for some reason, would stop working after I restarted MX. When I would go in an edit the DSN, I noticed the wrong data was set in the fields. At first, I thought it was Mozilla and it's "auto-form" fill-in thing, but it turns out I was wrong. Steven Erat of Macromedia suggested that I check out my jrun-resources.xml file and see if any DSNs were duplicated. Sure enough, I had multiple copies of multiple DSNs. I removed the duplicates (after first shutting down MX of course), and when I restarted, my DSN worked just fine. Steven gave a long explanation of why this is so, but for now, I'll just post this tip as something to look for. Of course, the usual warnings apply when working w/ MX's native XML files.