Comment 2 for bug 835103

First, I would have a look at the XML of some submissions marked as invalid. I have noticed a <udev> tag in some cases, so I would confirm this is the case.

Second, assuming there is indeed a <udev> tag, I'd make sure that the schema validator supports that tag. Then, make sure that the parser actually does something with that tag.

I suspect that might be a likely candidate to explain all the invalid submissions.