We now (again) have a working eXist 1.1.1 on Lettuce, with the exception of one problem, which I describe below. It's not a show-stopper, but it has been noted by one other user on the eXist newsgroup, and Wolfgang is looking at it. This is the issue:
Whenever we add a file to the database, or update a file in the database (using the admin client or the Web admin interface), the collection index becomes corrupted; most often, only the file which has been updated or changed is available to XQuery operations, so it's as if all other files in the collection disappear. Doing a reindex operation solves the problem.
There is a hack solution (replace the exist.jar and xmldb.jar in the Cocoon/eXist distro with those from one of the other distros), but we have always intended that the Cocoon/eXist distro be stable and well-maintained, like the other distros, so we do want Wolfgang to fix it.
Spent some time diagnosing and describing this on the list, and sent a longer explanation to Wolfgang with instructions on how to access our db and reproduce the problem.