Changesets following this one on 2011-06-16 improve subject search and title search, add keyword search and try to keep query speed acceptable.
This type of search should not be in version 1. It's not efficient enough for large databases (I'll get back on this in the development forum). But I think it will work for all libraries currently using version <= 0.7 because the databases are not large. Queries become slow when the biblio_field table gets very large, but it's hard to get to this point. Anyone imported more than 20.000 MARC records?
For obiblio-10-wip it's a completely different issue.
I don't think the SQL parts in the obiblio-10-wip source code are to blame for not returning the expected results. The expected results are returned when an obiblio-10-wip style query is constructed manually and executed directly on the database.