There was a fix in DMX 5.3.4 regarding permissions on the root folder (called Document Exchange) and how it renders in Template View. Unfortunately this introduced a new bug that was even more important. In 5.3.4 it has become impossible to add to the root folder. That is the only fix for this release.
As always you can find the latest copy here:
http://www.bring2mind.net/Downloads.aspx?EntryId=1589