DatabaseMetadata problems

I am trying to retrieve information about the structure of the database
using the DatabaseMetadata class. I am using version 7.1.3 and the latest
JDBC Drivers I can find. I got similar results with the versions supplied
with Mandrake 8.0 (7.0.3 and associated drivers)

The problems are:

1. No Index information from the getIndexInfo method
2. Indexes included as tables in getTables
3. Only one column in the entire database is returned in getColumns
4. The catalog name is not returned in getTables
5. Comment columns contain 'No Comment' instead of null

I have tried many variations in the parameters, but would prefer
catalogName = catalog, schema = null, and tableName = table (where
appropriate).

None of these problems have occurred on Sun's JdbcOdbc Bridge, Oracle's or
MySQL's drivers, so I am fairly confident that my code works. Is there any
chance of getting these problems fixed? Where are the sources, as I am
willing to take a look at them to try at least identify the problems in
more detail, even if I don't know Posgres well enough to actually fix them.

Thanks,

Tom