As far as I can see, all my JSF tags end with '/>', and there may or may not be a space before the '/', although I don't think this matters. The line numbers printed out in the message don't seem to correspond to any of my code, and must be related to the code in the jar files.
These only seem to be warnings, as my code otherwise works, and I've made considerable progress since the posting on file uploads and iframes.
Some suggestions would be appreciated. If there is no easy way of dealing with this, then provided the code works, I suppose it can be left.