Hi George, Thanks very much for the offer. Today, I did what I belatedly realized I should have done before I started musing in public about a phantom parser cache ;-), and tried my datatype .jar on a colleague's "virgin" (no previous such datatype .jar) Oxygen installation. Didn't work. That settles it for me: there's definitely something wrong with my .jar. What, I still don't know. I'll look into it. If I feel I'm at a dead stop, I'll take you up on your offer (thanks again). When I have a working datatype .jar that I can reproduce, I'll make it publicly available, probably via the GitHub repo unsoup/validator. Cheers, Graham Fundi Software Pty Ltd 2016 ABN 89 009 120 290 This message has been scanned for malware by Websense. www.websense.com