Yesterday I upgraded my openfire server to version 3.6.0 and found an error in the mysql update scripts (I suppose the same problem will appear with the scripts that builds the database from scratch)
The problem is the jid column in the ofRoster table (previously called jiveRoster). It is defined as a varchar(1024) but mysql converts varchars bigger than 255 chars to text (see http://dev.mysql.com/doc/refman/5.0/en/silent-column-changes.html). Now, the error occurs when an index is defined over this column because, in text columns, the index has to be built over a fixed prefix of the column length. So this sentence fails:
KEY `ofRoster_jid_idx (jid)
and must be changed to
KEY ofRoster_jid_idx (jid(100))
or whatever prefix length the index is going to be built for.